Condition type for pricing procedure

Hi,

I have a requirement where the condition type should only copy the value of the condition above it.

Eg I have 3 condition types PB00, Z001(Manual entry possible) and Z002 (tax)

PB00 - Rs 100

Z001 - Rs 100 Z001 should have the same value as PB00

Z002 - 2% on Z001. if Z001 is changed then Z002 will calculate the tax on the changed value.

regards