All my worksheets now appear with numbers in the column labels. e.g. instead
of a cell reference being A1 it now appears as R1C1. When developing
formulas, the cell reference counts the number of positions I've moved the
cursor. For instance if I move two columns to the right and two rows down it
is referred to as R(2) C(-2) - two postion move backwards from the origninal
column and two rows down. This makes it impossible to identify the cell you
are pointing to in a formula. How do I change the column back to the letter
system?