Essentially I would like a given key combination to give a key, so, say shift+left arrow would give an application the "home" key. and shift+right arrow would give the "end" key.

I'd also like to figure out characters using this without changing the keymap I'm using. so, shift+alt+c might give Ç, just as an example.

I have searched extensively through the openbox docs, and have looked at other lower-level configurations (such as x config files) and am unable to find anything on this subject. Has anyone else tried this and met with success?

It would ideally be a low-level solution for portability with gnome, kde, etc, but I think openbox can do this, if I knew how to modify the config file. The config file for other keybinds is ~/.config/openbox/rc.xml (for binding keys to programs, etc.) which I would guess is the file I need to use for this.