[SR-Users] how to drop 200ok and survive?

Hi, for some strange reason, ask my regulator.... i need to manipulate certain calls. the scenario goes like this: 1. caller sends invite to kamailio. 2. kamailio transfer the call to asterisk. 3. asterisk send progress and play "hello". 4. asterisk creates a new call (dial) to the same kamailio with destination callee. 5. the callee answers the call. here, i need to block the 200ok. so that the caller does not receive it. i managed to block it with t_suspend(). but, there is no bidirectional media. the 183 progress was sent with sendreceive. it seems the asterisk is waiting for the ACK in order to open both ways for media. i tried to use uac_send_req() but it is being sent with no to tag. and when i try manipulating the uac_req(turi) it does not help because it takes all the string i entered and wraps it with <>. any ideas? BR, Uri