[SR-Users] Delaying 200 OK sent to originator

Hey Guys, I came in need to delay 200 OK sent to originator, I know that is not the job of a proxy (not a perfect world though), so if anyone think that should be in theory at least possible with kamailio/sr, I would appreciate any tip. Scenario: User A -> Proxy -> User B. User B will send 183 and then 200 to the User A. I would need to delay the 200 OK sent to User A with a number of seconds, but still send ACK to User B to "fake" the receiving of the message in time. When the ACK for the delayed 200 OK comes back from User A, I would simply absorb it. Would that be possible with kamailio/sr without using an external application? Ta for any kind of tip! DanB