at the risk of sounding like a broken record, this is something else I've hacked with my "pd-string" externals: strings as lists of ASCII-valued floats -- I can post a patch for text2d which adds a "string" message, if you're interested.
well, it seem that a string data type in pd wouldn't be a really bad idea ... for me it wouldn't be necessary, since i fixed gem's symbol handling, but it might make sense to introduce your strings to gem's textbase class...
cheers ... tim