asterisk users - Jan 2006 - dialing 2 channels at the same time with different callerID number?

Can anyone think of a way to dial 2 different numbers at the same time,
but set the callerID number differently for each channel?

The application is a simultaneous ring of an office extension and a cell
phone where the user wants to know that the call to the cell phone is a
redirected call from the office.


Maybe the use of a "local" channel with changed caller ID behavior as
the second channel dialed?

To add additional complexity, I need to be able to pass an argument to a
macro to enable/disable this "feature"

TIA 

Damon