VBA Tip: Ban the Selection of Multiple Cells
A solution to ban the user from selecting multiple cells at once is simply to add this single line of code in the event Worksheet_SelectionChange of the sheet where the ban should be applied:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
ActiveCell.Select
End Sub
At each change of selection, the active cell will be selected (ActiveCell = 1 cell).