Yesterday, I posted a message on here and received a
number of good responses from Bernie Deitrick and Tom
Ogilvy (Thank you to you both). However, due to the fact
that I probably didn't state what my problem was too
clearly (as i was trying to keep it simple) I still have
not yet achieved my ultimate result.

So today, I am going to try and be a little clearer to see
if I can achieve what I am setting out to do.

My spreadhsheet contains a number of columns.
Column A normally has an id in it. Where it does, column
N is populated with a value. This value is the difference
between two other columns (column G minus column C),
although this field is already populated before the data
gets into Excel (it is calculated in Access).

On a number of rows, column A is blank/null, however,
there is data in the other columns on the corresponding
row. What i want to do is write a formula in column N
that calculates the difference between column G and column
C WHERE column a is Null/Blank. Where column A is not
blank/null, I do not want to overwrite the value that is
already in the cell.

Thanks in advance

Steve