I did a search and couldnt find anything so if this is a repost, forgive me.
.addtrainerspell <spell id> <training cost> <required spell> <required level> <delete spell>
the first one is the spell id, obvious enough
the second is the training cost, in copper. 0 results in no cost. 1000 is 10 silver
third is required level to train for the ability. Again, speaks for itself, 0 results in no level requirement.
Delete spell I am not sure about but I know 0 means it stays and 1 means it removes itself or something? Im unsure of this one so play around with it.
.addtrainerspell 11111 10 0 20 0
gives the trainer spell 11111 and it costs 10 copper and you need to be level 20 to learn it.
This helped me alot when i made custom trainers and for those of you who dont know, im sure this helps.