Depending on the modelling program if you color the parts you want to texture a different color and export the parts in one operation you will get a single object with no movable parts but with material groups for each component. You can then import to poser, retexture all the material groups and save it as a prop. For a removable lid for example just export as two objects, import to poser and parent the lid to the container. When saving to the prop library select both container and lid objects.