[PD] external returning its own path

[Joel Matthys]

Hi all. I'm working on a Pd external which encapsulates the audio 
language RTcmix, based on Brad Garton's [rtcmix~] Max object. The 
language and its audio functions are in a dylib in the external's directory.

My problem is that the external needs to know its own path in order to 
correctly find and reference the dylib. Max has nameinpath() and 
path_topathname() which help with this. Pd's open_via_path() won't work 
here because the path is the unknown.

Does anyone have a suggestion about how to access the external's path 
dynamically?

Thanks!
Joel