How to set one condition type active and inactive another automatically?

Hi all expert,

Problem:

I want to config a condition type, which will be inactive when another condition type active.

I've tried the exclusion condition, but I just want to have my own priorty, which not choose by the system.

For e.g

Condition type:

ZPXX

ZPX2

ZPXX wil inactive if the ZPX2 exist, which retrieve from price table.

and ZPX2 is calculated by routine 909.

I've tried using the Requiement routine to check the subtotal field XWORKD, to determine whether ZPXX have value, then inactive (sy-subrc = 4.) the ZPX2.

But it fail, the XWORKD does not have value when the pricing procedure start.

Anyone can help?

Terry