Convert cells(1,1) into "A1" and vice versa
The Address property of a cell can get this for you:
MsgBox Cells(1, 1).Address(RowAbsolute:=False, ColumnAbsolute:=False)
returns A1.
The other way around can be done with the Row and Column property of Range:
MsgBox Range("A1").Row & ", " & Range("A1").Column
returns 1,1.