Need Help Getting Forumla To Follow Contents Of Cell

Hi,

I just joined this site. Sorry if this thread is in the wrong place or if I'm doing something else wrong (this is my first forum site).

Here's my question - So if I have two excel files, one is called “sales” and the other is called “quarter 4 2016”. In the “sales” file there’s a cell with a formula that equals cell A1 in the “quarter 4 2016” file. If I move cell A1 (and it's contents) in “quarter 4 2016” A2 (still in quarter 4 2016), I want the cell in "sales" that before equaled A1 in "quarter 4 2016" to update and change to now equal A2 in "quarter 4 2016".

I know how to do this between different sheets in the same workbook, but not between different workbooks.

Thanks!