Pricing procedure in SD

Hi,

I have created 4 new condition types ( ZC01, ZC02, ZC03 & ZC04). [ surcharge condition types ]

condition records are maintained for ZC01 & ZC02 i.e. Rs 20 & 10 respectively.

ZC03 is the discount condition type and it is manual entry.

Now i required to save the sum of ( ZC01 + ZC02 - ZC03) value into condition ZC04. i.e. ( 20 + 10 - 5) = 25.

In pricing procedure i have maintained the conditions as follows, but still i am not getting the sum of 3 conditions into 4th condition type.

Step no. | Condition type | From | To

01 | ZCO1 |

02 | ZC02 |

03 | ZC03 |

04 | ZC04 | 01 | 03

Is this correct ? or i have to write the routine to move the value to ZC04.

Please guide me.

Thanks

Bhanu