Not possible unless using special things for every browser depending on them ... scripts/applets etc ..
So consider that :
1?/ you can't move the mouse by code
2?/ you can't managed effect with mouse (cursor and good X/Y pos) if out of game area
If you want to use mouse as a gamepad you can try using "touch" (in mouse mode) on a game area objet where "mouse" management is required but also the problem is that "click/touch" is needed to have data ... the good thing is that make your game "touch" compliant for "mobiles".