Chaining CTelephony Method calls

Hello to you all ,

( CARBIDE.C++ 1.3 , Symbian , s60 3rd FP1 , Nokia Interface )
Is it possible to do the following :

Create AO who listens to outgoing calls.
if such a call is detected , hangup that call and call a different number .
if the phone is ringing , auto-answer and send on the active call DTMF .

I know that each operation is asynchronious .
can i call AO inside an ongoing AO or must i cancel the previous one ?

I was thinking to do it this way :
1. Create AO - iListenToOutgoing and pass it the iTelephony.
2. afterwards call method "iListenToOutGoing::RegisterNotification" which listens to EVoiceLineStatusChange event .
3. now this method is set active. iListenToOutgoing::RunL() will be called if such event happens , right?
4. inside that method (RunL() ) i will create an AO called iKillCall which i will pass the same iTelephony and the iCallId .
5. iKillAll will call CTelephony::HangUp() method and then it will create an AO call iCallService and call method "CallNum".
6. "iCallService->Call Num" will MakeNewCall() to a pre-arranged number .
7. if that call is successful , iCallService->RunL is called and inside it i will call SendDTMF() and listen to call termination.

My Questions are :
1. is it the right order of things?
2. should i call the DoCancel() methods of each AO in the same place i declared it in order to CancelAsync() ?
3. should i create all this AO one after the other in AppUi and call it the day ?

I can really use your help and advice .

Thanx and have a nice week!!!!