Formulas In RS Like In Crystal

ive come from a crystal background and im having difficulty writing reports.

An example of the problem im having is with saved formulas (crystal calls them formulas)

eg

i would create a forumula called Difference

it would be something like this

=DateDiff("d",Field1, Field2) save that and then it was stored

then in a text box i would reference it like so.


=iif( Difference <= 23,"Too New","Just Right")

is this possible in RS??? as i have reports i need to convert from crystal to RS, and the iif statements are becoming huge, especially when you reference the same formula in the expression multiple times.


bit long winded i know, and i hope this makes sense, but i am witts end with this issue

thanks in advance

Jonny