Thanks Joerg,
I think that this will work, hwoever I'm having a little trouble getting it
to work, I went into VBE and inserted a module, cut and pasted what you wrote
then put in my starting number in cell A1 and went to the print preview
screen and nothing happened. I did manage to get it to work once at my
office, but when I tried it again at home it wouldn't work. I followed the
steps to the letter on the office help site on Creating my own worksheet
function but I must have done something different when it worked(obviously!)
and I cannot for the life of me remember what I did! If you could let me
know what step I am missing it would mean my undying gratitude! Thanks in
advance.