There are various options for getting your character from Poser to 3DSMax where we can manipulate it and rig it ready for finally exporting to Cal3D for use within a real-time applications.
However, the least problem-free method uses a 3DSMax plugin called GestureMax which is designed to import native Poser files (*.pz3) directly into 3DSMax. There is a fully-functional 15-day / 10-use trial version available at the link above, and there is a fully licenced version installed on the machine in the CAVE office.
Use 3DSMax8. The exporter from 3DSMax9 to Cal3D is prone to crashing and will drive you completely mad.
