asterisk users - Sep 2005 - "Non-blocking" Dial (and other commands): is there a way?

In order to use a with GrandStream BT-488 as "pass-through" gateway, I
need a way of sending the FXO port off hook when I'm using the FXS port
for VoIP communications, because I want to use the "hunting line"
feature
to let incoming call skip that FXO port and move on to the next free line.
The only way I have found to engage a device without getting blocked until
the call ends passes through an AGI script that drops a callfile into the
/var/spool/asterisk/outgoing directory, telling Asterisk to dial the FXO
port and then connect the channel to, say, the MusicOnHold() application.
When I'm done, I can then issue a SoftHanghup() to the FXO device. This
method strikes me as pretty clumsy: aren't there better ways of issuing
commands from the dialplan in "detached mode", perhaps getting a
handle
useful to regain control later, and proceed to do other things?

Enzo