how to connect astguiclient with extensions.conf

Hi,
I want to know as I can connect my phones(astguiclient) with variables TRUNK of my extensions.conf
For example:
I want that my I phone 105 calls through Zap/g5. since I make the relation through vicidial manager?
I want to know as I can connect my phones(astguiclient) with variables TRUNK of my extensions.conf
For example:
I want that my I phone 105 calls through Zap/g5. since I make the relation through vicidial manager?