Dynamic worksheet source for Pivot Table

I have an Excel doc that's a budget--each month we just copy the previous month's sheet to a new sheet, and rename it for the current month. My wife does that part, and fills in most of the info, so unfortunately I really can't change that process.

I want to put a pivot table on the sheet that will use the first three columns as its source. Works great, except that when we create the next month's sheet, the pivot table is stuck pulling its info from the sheet we copied. Is there a way I can create that table so that it will always use its own sheet as the source? It will always be using columns ABC.

Sorry if this has been described before. Seems like it must be a fairly common need, but my search skills couldn't uncover a request for it.

Thanks.

I tried it and it didn't seem to change anything at all. Your results wouldn't really work either, of course, since there's no use having a pivot table that doesn't function as a pivot table. Unless I'm misunderstanding you.

OK. Anyone else?