Macro to apply a format to every cell containing only a single character

Hi,

Please excuse my spamming this board; I notice my last post is still at the top, but that issue was solved so quickly and with such aplomb that I couldn’t resist trying again with a new problem.

I have a spreadsheet with two columns of data which will be entered by the user alphabetically. There are headings ("A", "B", etc) at intervals down the page which go over both columns and because of conflicting code I need the headings to be centred across selection rather than merged.

What I want is a macro that finds every cell containing only a single letter, and then applies a format to that cell and the empty cell in the column immediately right of it so that the text appears centred over both columns.

I've tried to do this with conditional formatting but it doesn't seem to be an option.

Thanks.

insert simple macro in standard module (Alt+F11 Insert->Module):

Sub test()
Dim rng As Range
For Each rng In Selection
  If Len(rng.Value) = 1 Then rng.Resize(1, 2).HorizontalAlignment = xlCenter
Next rng
End Sub

Go back to your spreadsheet, select column with headings (for instance A1:A123) and run the macro (Alt+F8)

Thank you. If I preset the range is there a way I could make it run at regular intervals so that the user doesn't have to update it?