You didn't give us a lot to work with, but I think you are looking for
something like this...

=IF(<<your condition,<<formula with x=y,<<formula with x<y)

--
Rick (MVP - Excel)


"H.G. Lamy" wrote in message
...
Hello,

depending on a certain circumstances, a formula must change from "X = Y"
to "X < Y".
Can this be done (e.g. using "if", or otherwise) ?
Thank you in advance.
Merry Christmas,

H.G. Lamy