Hi PapaSmurf, welcome to the board!
How about this for selecting the previous sheet ...
Code:
On Error Resume Next
Sheets(ActiveSheet.Index - 1).Activate
You would need the On Error Resume Next statement if you were on sheets(1) when you ran this code. You could make it so that it would loop to the last sheet, and vice versa with the last sheet going to the first. If you'd like ..