Druid - mages

I'd like to be able to figure this out. I tried modifying the basic dualclas.2da file to allow for this as a dual class option, but obviously in the case of a druid dualed to a mage this doesn't allow characters to actually cast any mage spells (the learned spells appear but are darkened out). So any thoughts as to how I would go to proceed to get this entirely legitimate combination working would be appreciated (it is actually legit under 2nd edition rules :D ).