Stupidity removed 
Instead of what you have, try something like this:
on $*:TEXT:/!onair ([\w\s]+) - ([\w\s]+)/:#: {
if ($nick isop $chan)) {
var %1 = $regml(1), %2 = $regml(2)
;
; ...from here, use %1 as $1 and %2 as $2...
;
}
}
If it's okay for the values to contain spaces, then leave the
\s in both the ()'s of the event. Otherwise, remove the \s from the ()'s.
If neither values are supposed