I have done this any number of times for experiments and whatnot.. the long and short of it is: you will never get a very good result using poser models and decimating them. You can get a decent result appropriate for testing, but nothing that will be particularly professional.. the reasons are simple, automatic decimation will never be sensitive to animation needs...

Basically a decimated model may look good, but will almost never animate well. You are better off exporting your poser model, and recreating it entirely by hand in your model program, using the poser mesh only as a guide. This way you get the correct seams and faces, and there is no copyright problem.

You can however, export poser animations and convert them to a 3DMax biped file using some conversion tools..they can be useful.