default location for opendialog?

Hello,

I'd like to launch some opendialog objects with a default location,
to avoid to navigate among different directories since I know the
exact path to search in. With 'path' -> [thispatcher] I easily get
the parent directory of subdirectories I'm interested in (like
"Audio", "Colors","Presets" or "Scores"). But I don't know how to use
these paths with the opendialog objects I use. Do someone know?

Thanks,
kb