Dynamic formulae calculation in RPG

Hello All,

We have a complicated Invoice calculation process where a lot local taxes 
are to be considered. In order to make these calculations dynamic I plan 
to do the calculations using dynamic formulas so that any future changes 
can be considered.

Eg:

Description             Name            Formula         Value
Base value              Base            Qty * price             1000
Tax1 20% of base        Tax1            Base * .02              20
Tax2 30% of Tax1        Tax2            Tax1 * .03              0.6
Total                   Total           Base + Tax1 + Tax2      1020.6


Has anyone built something like that & can share the code - I can save 
some time.

Thanks & best regards
Ewart

This e-mail is confidential and it is intended only for the addressees. 
Any review, dissemination, distribution, or copying of this message by 
persons or entities other than the intended recipient is prohibited. If 
you have received this e-mail in error, kindly notify us immediately by 
telephone or e-mail and delete the message from your system. The sender 
does not accept liability for any errors or omissions in the contents of 
this message which may arise as a result of the e-mail transmission.