how I play the MP3 audio output call audio input

[lanlangliang]

I just bought a Windows Mobile phone,and I want to add a application to my
phone to do such a small thing: When the others phone in, my phone would
play a MP3 in my phone to the caller automaticly until i answer it.

Now my trouble is: how to play mp3/wav to the caller not to the speakers.

thanks a lot.

 

[rfernandez]

I don't believe you can do it, since the calling tone is defined by
the network operator. The only solution would be having an application
that answer the incoming call and plays the specified track until the
user decides to pick the call. But that implies in undesired costs for
the caller. I would hate it!