Auto Determine Range to pass to vlookup

Hello all,

I'm trying to use vba to determine the range of a worksheet so that the range includes all data on the sheet.

I've found the following code to determine the bottom, right most cell

Function FindLastCell() As String

Dim LastColumn As Integer

Dim LastRow As Long

Dim LastCell As Range

Dim rngResult As String

    If WorksheetFunction.CountA(Cells) > 0 Then

        'Search for any entry, by searching backwards by Rows.

        LastRow = Cells.Find(What:="*", After:=[a1], SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row

        'Search for any entry, by searching backwards by Columns.

        LastColumn = Cells.Find(What:="*", After:=[a1], SearchOrder:=xlByColumns, SearchDirection:=xlPrevious).Column

        strResult = Cells(LastRow, LastColumn).Address

        FindLastCell = rngResult
        
    End If

End Function

The problem is that the function returns a string, not a range reference.
i.e. if the 'ctrl-end' keystroke were to take me to cell 'AM68' the function returns a string
'$AM$68'.

It seems to me it should be a trivial process to turn the info into a range object, but I'm really struggling here. Any help would be appreciated.

Once I have the range I want to replace the hard-coded range reference is the code below

strResult = Application.VLookup(strBlendNum, Range("a1:am68"), intBlendColorColumn, False)

Thanks in advance for your help.