Creation of Custom Functions

Hello everyone;

As the title hints, I'm looking to create custom functions to be used within a workbook. Let me explain my situation:

I have a single equation that may change. I will rely on this equation across multiple sheets within the workbook. I would like to utilize a central repository to change this equation, and automatically have it cascade to other worksheets.

This equation will be about 3-4 lines of imbedded if functions, with different equations depending on a single input variable. Additionally, the pages that will utilize these functions is not consistent within the worksheets, so for data consistency, I would prefer the central repository.

Any guidance or recommendations for accomplishing this?

Have a look at this link: http://www.eggheadcafe.com/software/...ormula-fr.aspx