Format of incoming Number

Hello!

Have the following problem:

My Provider (A1) send me the Number in the format +43664 xxxxx. I need the Number in the format 0664xxxxx.

Aslo i upated 2 lines in the extension.conf:

exten => s,10,SetCIDNum(0${CALLERIDNUM})
exten => s,11,Dial(${ds})

I need this for add a 0.

Can someone tell me, who i combating both expressions.

Thanks.

Cohibig