There should be an easy answer to my problem. I load a figure (M4) in Poser. Next I go to the Materials Room and create a new node for a texture map. Then I connect the node to the Diffuse Color. Here's the problem. I can't select the entire body. Only parts of the body can be checked in the pull-down menu. The bodymap applies itself only to a part. What am I missing? Thanks...

Yes, that is the tedious way of applying textures manually.  You can do it for one zone, right-click and select all, right-click and copy.  Go to each zone that shares the same textures, right-click and paste.  There are three major texture files to apply, torso, limbs and face (which includes mouth and teeth).  Avoid, using the apply to all parts, that will simply apply 1 texture to all the zones.

MATPose files and Material collections will apply the correct maps to all body part zones.  That is what they are designed for.