Yes, using the Figure Setup pane.
Load and select V4, then from the Figure Setup pane’s option menu (button in the top corner, or right-click on the tab) Copy From Selected Figure. Since this is the Poser V4 figure, select the Poser preset for the OBJ when prompted (to be on the safe side, though you will be removing references to the V4 OBJ in any case)
Right-click in the Figure Setup pane’s Geometry List panel and choose Add Geometry, then set the options as you did for importing the OBJ into the scene.
Drag the OBJ’s entry from the Geometry List onto the root of the V4 figure in the Relationships panel.
Right-click on unwanted bones to delete them. For bones you want, but which don’t have groups in your OBJ (for example, if your sleeves end with the forearms you probably want to keep the hand bones) right-click on the entry under Geometry and select Remove Geometry Reference. If you want to add handles you can create new child bones by a right-click too, or if they have groups already by dragging the bones to the right place in the hierarchy..
Rename the figure by clicking on the name.
Check Modify Selected Figure at bottom left of the pane. Click Create.
You will need to adjust the joint settings for each of the parameters with the Joint Editor Tool - but make sure you leave the centre and end points alone.