You could have a special tune on the empeg with a recognizable name, and when Hijack detects from the "notify" output that this song is starting, it performs a button combination?
I think that if we want tunes to to send commands to Hijack, the appropriate place for such commands is in the COMMENTS field of the tune (if I recall correctly, the comments do appear in the notify). That way, we could have special-purpose tunes that do certain things, OR we could just tag regular tunes with special commands.
I've already discussed this idea with Genixia privately (a long long time ago), but I'll throw out some examples of things you might put in the Comments field that could command Hijack:
{Hijack:Bass=+3}
{Hijack:Treble=-4}
{Hijack:EQPreset=7}
{Hijack:VolAdj=Med}
{Hijack:InsertFid=1af3}
{Hijack:AppendFid=3dc1}
{Hijack:PowerOff}
{Hijack:SelectTuner}
Some of those things could apply to just that one tune. For instance, imagine that you have one song where you want the bass boosted, but then have it go back to normal after that tune is done playing.
Or you could have a particular song set up so that when THAT song comes on, Hijack automatically inserts a certain song after it no matter what. (Useful for song pairs that work well together or that flow into each other.)
There are all sorts of possibilities. It could almost be a scripting language... HMMMM....
Also remember that you can group-select tunes in emplode and apply comments to the group. So if you want to boost the bass on a specific album, it's easy to do.