Hi,
Target value is in contract header. There can be multiple PR's referenced in the same contract. In this case, if you are copying the value from PR to contract, how the target value has to be calculated.
As of my knowledge, there is no provision to get the target value in contract header from PR, since PR is item wise and the target value is at contract header.
You may go for user exit, but you should consider the point in case of multiple PR referenced in same contract. You may develop a new field in PR header / item and give the logic in such a way that the sum of all items value to be copied to the contract header.
Regards,
AKPT