I'm afraid you miss the point:
I did lead Apache to pointhttp://sub.domain.com tohttp://www.domain.com/modules/sub .
I get to the right place ... but I get this massage since XOOPS is defined to "know" "what module" + "module permition" by parts of the url .
I think the only "good way" to bypass this is using rewrite rules, but I still havn't done it right !!
JIJOE's post @ PEAK XOOPS supply a clue ... but not exactly what I need ...
His simple solution for turning "/modules/" into "/md/" is elegant and very nice ... needs a rewrite expert to turn it to my needs