Ah, after a little research and testing i found a solution. Now I just need to implement it... :-)

I need to send:
That sends "connect held and active (or MO alerting) call with each other (locally both calls are disconnected)".

I've tried it out with a terminal and send it through pnatd and it works fine.

Now I just need to put a widget/button somewhere easy accessible from the call-program...

/Fredrik