Alex
Depends whether it is from the Control Menu (ActiveX) or Forms Menu.
If it is ActiveX (Controls Menu), write the code in an event for the control - probably the "Change" event.
To do this:
-Open Visual Basic Editor (VBE) (Atl + F11)
-in Project Explorer double click on the Sheet name
-Code window for the Sheet will open
-Click on the left drop down at the top of the code window
-Select the name of the ComboBox
-In the right drop down, select "Change"
-Write your code in the event procedure
If it is from the Forms Menu, write your code as a macro, then:
-Right click on the ComboBox
-Select "Assign Macro" from the Menu
-Select your macro name to attach it to the ComboBox
Any help?