Is there a way to define external viewers for files, e.g. a list of the kind: pdf /usr/bin/acroread text /usr/bin/gvim mov /usr/bin/xine txt internal [mM]akefile internal TODO internal .... Get the drift?. If there isn't such capability
theres something like this for gnome, where if you run 'gnome-remote /path/to/some.pdf' it will launch evince. osux has something similar, called 'open' i think. on windows, im not sure what you do, maybe 'exec explorer.exe filename'..
im pretty sure pd just uses the tk_fileChooser so youre going to have to figure out how to override its default somehow.. maybe check the tk docs? and check pd.tk. its surely no more than a few lines to do what you want, on all the platforms..