hi
In the formula editor on the left hand side there are options "Report Custom Functions" & "Repository Custom Funcitons" In this you can create your own custom function. you can add this custom function by clicking the "Add to repository" on the menu bar. This will add to the repository and can be used in any report on the network and stand alone machince. But i m not sure if the you change the exisiting custom function and that reflects in your old reports. Please check this option.
Edited by Savan - 18 Jan 2008 at 4:22am