HP Intelligent Management Center Standard Software Platform - Manual (Page 574)

5. In the Custom Function area, choose the custom function you want to
base your formula on.
You can choose a Report Custom Function (a custom function that exists
in the current report) or a Repository Custom Function (a custom function
that is stored in the repository).
Note:
If you select a Repository Custom Function, that custom function is added
to the current report. If that custom function requires other custom
functions from the repository, they can be added as well.
6. In the Function Arguments area, specify a value for each argument in the
appropriate Value field.
You can enter constant values directly, or you can select predefined
values or report fields from the associated list.
7. Click Save to save the formula to the Formula Fields folder of the Formula
Workshop.
You can now use this formula in your report just as you would use a formula
you created in the Formula Editor.
574 Crystal Reports 2008 SP3 User's Guide
Using Formulas 22
Creating and modifying formulas