I have a sort macro. How to add script to preselect rows to sort based on column value?

I have a macro which performs a sort for me.

I have it set up to perform the sort on whatever rows are preselected by the user.

I would like to have the macro preselect the rows to sort for me, based on whether there is any value in a certain column (it will always be the same column, 'G'). All cells in column G presently contain either nothing, or a number between 1 and 20. I prefer the macro select rows based on whether there is any value in cells in column G at all, as I may add additional numbers later.

EDIT: Oh, and if it helps, all of the rows with a value in them will always be contiguous to one another. All of the blank cells are at the top and bottom (but those exact locations vary.)

This is what I'm using that I want to add on to.

Sub Sort()
'
' Sort Macro
' Sort based on column 'G'
'
' Keyboard Shortcut: Ctrl+m
'
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Clear
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Add Key:=Selection.Columns(7), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Add Key:=Selection.Columns(4), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Add Key:=Selection.Columns(3), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    With ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort
        .SetRange Selection
        .Header = xlGuess
        .MatchCase = False
        .Orientation = xlTopToBottom
        .SortMethod = xlPinYin
        .Apply
    End With
    Selection.Rows.AutoFit
End Sub

Thank you for your help. I'm a total rookie at this VBA stuff. But at my small firm, I'm the default "techie" by virtue of everyone else being even more clueless than I am. lol

1) Fetch row numbers:

    GTop = Range("G1").End(xlDown).Row
    GLast = Cells(GTop, "G").End(xlDown).Row

Or,
2) Fetch address:

    Range("G1").Select
    Selection.End(xlDown).Select
    Range(Selection, Selection.End(xlDown)).Select
    a = Selection.Address(0, 0)

Since I don't know what your worksheet looks like, assume that the sort will ALWAYS include columns A - H, with rows determined by G. Then

Sub BVJ()
    Dim GTop        As Long, _
        GLast       As Long, _
        MySortRange As String
    
    GTop = Range("G1").End(xlDown).Row
    Glast = Cells(GTop, "G").End(xlDown).Row

    MySortRange = "A" & GTop & ":H" & GLast
    
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Clear
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Add Key:=Selection.Columns(7), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Add Key:=Selection.Columns(4), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort.SortFields.Add Key:=Selection.Columns(3), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    With ActiveWorkbook.Worksheets(ActiveSheet.Name).Sort   
        .SetRange Range(MySortRange)
        .Header = xlGuess
        .MatchCase = False
        .Orientation = xlTopToBottom
        .SortMethod = xlPinYin
        .Apply
    End With
    Selection.Rows.AutoFit
End Sub

In post #1: "... EDIT: Oh, and if it helps, all of the rows with a value in them will always be contiguous to one another. All of the blank cells are at the top and bottom (but those exact locations vary.) ...". However, "... I was hoping for a script that would look at cells in column G, and would select entire rows with a value present in the 'G' column cells, and not select 'blank' cells. ..." seems to indicate that there may be blank rows interspersed??

Surely there is a way to have Excel look at column G and any time there is a value in a cell, excel would select that row. I figured it would require an if/then query. Something that starts at G1. If there is a value in cell G1, then Row 1 is selected. Then it would go to G2 and repeat, until the entire sheet had been checked, then it would perform the sort I've already got.

No. The blanks in column G are only at the top and bottom. The rows that will need sorted are always contiguous to one another... They are next to each other without interruption. Instead 0f the user having to grab all 0f those rows and then triggering the sort macro with CTRL+M, I want the user to be able to just hit CTRL+M, and have Excel find the rows and sort them all in one sub.

This is basically being used to sort a list 0f products and prices that can be just tens 0f lines long, or thousands, depending on the project. Obviously, it would be great to just hit a button and sort the list (the sort is used to group like products, so that those sub groups can be easily shown to the buyer), rather than having to scroll to grab all 0f those lines.

double post.

Two changes

 MySortRange = "G" & GTop & ":G" & GLast
.SetRange Range(MySortRange).EntireRow