How to call a macro when clicking in a specific cell from you personal macro workbook?

This is the code I use to call a macro when the macro Im calling is in the same workbook.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Address = "$A$1" Then Call ClearFormating
End Sub

However, I would like to call this same macro when using another workbook. I copied the macro "Clearformating" and pasted into a personal macro workbook module. However when I add this code to the sheet tab it will not run the macro.

I also tried this code.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.Address = "$A$1" Then Call PERSONAL!.ClearFormating
End Sub

Thanks in advance!