The attached is a solution from Saqib at:
This works wonderfully but I do not understand how value 10 enters into cell Formulas!L2 when September is selected from the dropbox at cell Sheet1!D2.
Basically, how this dropbox changes the value of all months to zero except the selected month (which is set equal to 10).
If there was an event associated with the drop box, I could loop through and do all these; but there is no event to work with.
Question: How this dropbox manipulates Formulas!D2:AA:2?
Also, when I pick Jan 2014, instead of setting cell Formulas!P2 to 10, it sets cell Formulas!D2 to 10. After I learn how the dropbox works, I may be able to handle this part also.