[Asterisk-Users] Dialling 9 for an outside line

[richard]

I have the following line in my extensions.conf which when I dial 100 
(from my BudgeTone 100, and then wait a few seconds) I will get an 
outside line.

exten =>100,1,Dial(Zap/1,20)

What do I need to put in the extensions.conf file so that I can dial 9 
(and then a number) and then Asterisk automatically dials 9 and then the 
number so that an outside call i smade?

Thanks

Richard