=IF(ISNUMBER(-C1),3,4)
If you are sure that the column C numbers will be real numbers, and not text
that looks like numbers, then you can omit the minus sign.
If you want to add an extra test for column C being blank, you can do that.
--
David Biddulph

"Colin Hayes" wrote in message
...

HI

In column C I have a list of reference numbers.

Some of these reference numbers only contain numbers and some contain
numbers and letters.

In column D I need to put a number 3 three for those cells in C which
contain just numbers , and 4 for those cells which contain combined
numbers and letters.

Can some one help with some code for this , please?

Any help appreciated.

Best Wishes