Basic Variable Question

Can someone give me a basic example of using variables that can be used on a different sheet but still reference their values on the sheet where all my data is.

If Cells(1,C) =”MobileReceivePower” Then
               Sheets("Sheet1").Cells(2, 11).Formula = "= Average(‘Series Formatted Data’!C:C)"

The above code posts the data on sheet1 in the cell I want however it is only posting the contense of column C which I can see why. I want to have it call it as a variable not the actual spot c. I dont need my whole code written by any means, I know you all have lives to live and wouldnt expect that from someone. Just looking for a point in the right direction. Any tips or answers would be greatly appreciated. Thanks

Side note: I did post a similar thread however I felt it was a bit vague and didnt really get to the heart of what I was stuck on.