I want to plug a range object into a formula. An example should look roughly like this:
Dim x As Range
Set x = Range(Cells(1, 1), Cells(2, 1))
Range(\"C1\")
You need
Range("C1").Formula = "=SUM(" & x.Address(False, False) & ")"
See also
http://www.dailydoseofexcel.com/archives/2004/04/16/worksheet-formulas-in-vba-part-i/
http://www.dailydoseofexcel.com/archives/2004/04/16/worksheet-formula-in-vba-part-ii/
Use x.address, that should do the trick