It would have to be more than just @ because that might already be a normal part of the comment field in some weird cases. You'd need a more unique identifier string that was more characters long. Like @EQPreset=XX, or <Equalizer=XX>, or HijackEQ=XX or something.

And I'd still rather see a Bass/Treble addition/subtraction rather than an EQ preset select... I suppose we could do both...