I believe that I have a wood screw which has got

If the screw is small enough to move around between the drum and the outer casing then the best way is to physically lift the complete machine and tilt it towards the drain hole in the tub, this will get the screw down into the pump area or hoses where you can remove the hose clips and hopefully the screw. To find out where the drain hole is remove the back cover and follow the pipe work onto the drum casing. If the screw is jammed then you will have to remove the drum from the casing completely. Good luck, let me know how you get on