I implemented a button that ask the user where to add a column, and the button takes the user input(A-Z) and generates the column until the end of the table NOT SPREADSH
you could try this:
Private Sub CommandButton2_Click()
Dim colIndex As Variant
colIndex = Application.InputBox("Enter a column that you want to add: ", "What column?", , , , , , 2) '<--| force a text
If colIndex = "" Then Exit Sub
With ThisWorkbook.Sheets("Sheet1").Columns(colIndex) '<--| reference column you want to insert
.Insert shift:=xlRight '<--| insert a new column , then the referenced one shifts one column to the right of the inserted one
.Offset(, -2).Copy '<--| copy the column two columns to the left of the referenced one (i.e. one column left of the new one)
.Offset(, -1).PasteSpecial xlPasteFormats '<--| paste formats to the new column
Application.CutCopyMode = False
End With
End Sub