Compare two sheets of Data and output Variance on New Sheet

Ciao All ~

I'm attempting to create variance tab for data pulled by UPC and Store for two time periods.

This is what I could come up with :

=SUM((VLOOKUP(VARIANCES!$A2,A!$A:$AY,2,0))-(VLOOKUP(VARIANCES!$A2,B!$A:$AY,2,0)))/(VLOOKUP(VARIANCES!$A2,B!$A:$AY,2,0))

Is there an easy way so I don't have to change the formula each time it's pasted into a new Column?

Thank you in advance.

Thanks for new title.

Maybe since the column numbers for the VLOOKUP column indexes correspond to the column the formula is in, you might say:

=SUM((VLOOKUP(VARIANCES!$A3,Table1,COLUMN(),0))-(VLOOKUP(VARIANCES!$A3,Table2,COLUMN(),0)))/(VLOOKUP(VARIANCES!$A3,Table2,COLUMN(),0))