hello,
please have a look on what I've done for gis plugin to choose the 'rubrique' or the 'groupe de mots-clefs'
to include the gis plugin where you need it.
It would be great that you put a cfg_gis on your plugin using cfg plugin.
let me know if you are interested, I'll give you all the code of it, it will not change anything if cfg is not active.
http://www.spip-contrib.net/Inserer-un-plugin-dans-une
++
touti