Oops. Well then, here's another approach.
PSP is only necessary for step 2. It's not very expensive ($85
to $109 at retail, depending on where you buy it). But if you're still in
"experimenting" stage, and not sure you want to spend that
much money until you confirm that you want to create your own Agents,
you can reduce your bitmaps' color palette by using the "Paint" program that's
built into Windows. (On my computer, running Windows 98SE, it's at
Start>Programs>Accessories>Paint.) The output from Paint does not look
as good as the output from PSP7. Paint's output looks more like a character from
a color newspaper comics page, while PSP7's output looks very much like the
character you'll create with Poser 4.
Some cash investment is going to be necessary,
nonetheless, in order to purchase a full version of Poser 4, because the
demo version of Poser will not allow you to "export" bitmaps. I recommended
trying the demo version of Poser, because the demo will give you a taste of
what's necessary to create and animate new characters.