question for spawn modifying

[el_fatal]

Heyas! I have some problems modifying spawns. What I want to do is:
#npcspawn xyz --> spawn an existing NPC

then modify him with a new name, and some other behaviour.
Remove or add loot isnt a problem.
Problem is that with #npcspawn update i never get variables to fill in.
I know, that when I did all the changes I want I add him with #npcspawn add to the database, then repop to take effect.
But how to change name? maybe ai behaviour (can that be done "online"?) and maybe a new #gassign?

Thanks in advance for the help and forgive my questions - I just started to deal with all that!

El