UDF's return values. They can not change formatting nor can the effect the
values of cells other than the one that they are in.

Functions called from within code can do anything that they want however if
converted to a UDF then they are bound by the above rules.

A UDF has all of the abilities of any other function in XL like sum or
average. They operate within a single cell and just return a value to that
cell...
--
HTH...

Jim Thomlinson


"George B" wrote:

I know that I've read somewhere that there are some things UDF's cannot do.
Where can I find an explanation of those limitations? Using Excel 2000, I'm
trying to change the numerical format of the calling cell. Is this
possible?