I probably have a little unorthodox way of rigging my figures. I use Poser 5 also. But I used to use propack for the longest time.

Anyhow, I load my figure in and then start adding the bones so that it matches up to the figure. (Little things like teddy bears and mech-stuff don't need many bones and don't need to use a walk designer...) Although, a shortcut for you might be to go in to the setup room, and then pick the character in your library that would be the most similiar and then double click that character. The bones will be loaded in to the scene. Now, I usually move the skeleton around to get it overlaid on my figure and then move, bend, etc the bones so that they are as close as possible. Then I go to the grouper tool up there in the setup room and click auto group. It's never gotten it 100% for me, but it's come close. So, then it's just a matter of checking the groups and adjusting anything that might need to be adjusted. Then after that you can go back to the posing room and see how everything moves.

I learned all that from a tutorial a long time ago. (I think it was for ProPack... The tutorial.) But it's been a method I've used for a long time, but then again... What works for some doesn't always work for all. LOL!

Good luck with your model all the same. (It's pretty wicked looking!)