PCR on Constant for IT0015/IT0014

Hi Experts,

We have an requirement to write a PCR based on different constants.

Scenario: In IT0014 we want give EE band number (1,2,3 etc) under one WT ABCD and value should be pick up from Constant table (V_T511K) depends on number enters in WT ABCD in IT0014.

EX: WT ABCD created in IT0014

Standard premium/Allowance :

Band/Number 1 =Rs 1000 (Constant ZABC1)

Band/Number 2 = Rs 1500 (Constant ZABC2)

Band/Number 3 = Rs 2000 (Constant ZABC3)

Band/ Number 4= Rs 2500 (Constant ZABC4)

The above amounts have been maintained in Constant table.

Requirement: If I enter band Number 1 in IT0014, in RT table system should pick value as 1000 from constant for Number 1,If input enters 2 then value should pick up 1500 and for 3 it should be 2000 etc...

Could you please help me the logic to write a PCR on the above..

Many Thanks in Advance...