When you give a spawned creature treasure, notice they mention putting it in a pouch. You can click on the pouch and then type 'into it'. This will move you into the pouch where you can access the treasure. When you kill a creature, it doesn't actually give back the treasure, but instead copies it and drops the copy into its location. I realized this could be used to dupe pennies (create something worth all your pennies, give to creature, kill it, you are twice as rich, rinse and repeat). So they only accept treasure worth 10% of the spawned creature's worth. Of course one who enters the pouch can bypass the value check but I'm planning to tighten up the copy code to regulate this (it's not a big issue right now with so few players).
And you probably already know this... if you want to get back out of the pouch, scroll back and click on wherever the creature's name was meantioned and then 'goto it'. Or 'goto creaturename' usually works well enough.
One thing I'd like to do is change the go command to prevent people from moving through an exit if there is someone alive guarding it. That should allow some more interesting building, methinks.
Let me know if you have any ideas on how to improve the spawn template's code, incluing the way it works with treasure.