Right here, pal!
I'm not familiar at all with GlovePie's syntax though... sorry! But surely, some other REAPER users familiar with its OSC implementation are. Iirc, Anton9 is the man you should speak to on this one.
In any case, you should understand that the "@" is unique to REAPER, and NOT part of the OSC specs. REAPER will send a specific *number* (for the track, FX slot, or parameter used) instead of the literal "@" symbol.
So, on GlovePie's end, you should NOT try to use the "@" symbol AT ALL. You should either explicitly use numbers (1, 2, 3, etc.) in the OSC addresses corresponding to all different tracks, FX, and parameters (the 'dumb method'), or use *variables* which correspond to track, FX slot and/or parameter number, and then process the messages using those variables (the 'smart method').
Hth, for now!