Hi Ced, like Brian writes above it looks like you've already installed Max's CustomUI extension, so you have a button on your bottom toolbar labeled "Obj Library", it's for doing exactly what you describe.

The way you've tried to add it there is as a drawing command, a command is made of script code that does things like pick points, a .3dm file on the other hand is a data file they are not the same thing.

It could be possible to set up a button like you're trying to do but you'd need to make it use the import command with the 3dm file as a parameter to it, like command="Import c:\objects\myobj.3dm" . But since you have the "Obj Library" button all set up on your bottom toolbar already you should give that a try first.

- Michael