User exit for transaction IMA11

Dear friends,

I want to update the "user responsible" field of transaction IMA11 under the user fields tab.The updated "user responsible" has to be updated in table PROJ and PRPS.I have searched for the exits available.the exit AAIR0006 allows us to update PRPS table only.Can anybody suggest how to update PROJ in this case?

Solution will be awarded points!!!!!

Thanks,

Rajesh Sahal