[KissLick]

Can you direct me please? I was looking through SDK and didn't find anything what could do that... :-(

P.S.: Where did you find NET_SendPacket ?

[kadet.89]

server/bin/engine_srv.so (CSS)
If you are going to detour this function, I can suggest using this extension as a base:
https://forums.alliedmods.net/showthread.php?t=159876
If the data is not compressed here, than finding the offset of the property is not a big deal (artmoney method)