Insert column Text after first non blank character

I would like to modify this macro to insert a string character after encountering the first non-blank character in a column.
example: my data is in col A (The row count varies)
----------
"When working in Excel, you can often undo the actions "
"you must change it so that it references the directory "
disabled when saving a workbook
Pay special attention to range
You must click the Enable option in the yellow

I would like the output to be

"Insert HereWhen working in Excel, you can often undo the actions "
"Insert Hereyou must change it so that it references the directory "
dInsert Hereisabled when saving a workbook
PInsert Hereay special attention to range
YInsert Hereou must click the Enable option in the yellow


My current code

Sub addcomment()
 Dim Rng As Range
    Dim a As Range
    On Error Resume Next
           For Each a In Selection
        a.Value = Left(a.Value, 1) & "Insert Here " & Mid(a.Value, 2, Len(a.Value) - 1)
    Next
End Sub