Here is a function from the cloth demo:
function fire()
power# = 5000000
DYN SET LINEAR MOMENTUM sphereID, 0, 0, 0
DYN SET POSITION sphereID, camera position X(), camera position Y(), camera position Z()
camAngleX# = camera angle x()
camAngleY# = camera angle y()
xForce# = power# * sin(camAngleY#) * cos(camAngleX#)
yForce# = -power# * sin(camAngleX#)
zForce# = power# * cos(camAngle#) * cos(camAngleX#)
DYN ADD FORCE sphereID, xForce#, yForce#, zForce#
endfunction
You could also just set up the object facing the direction you wish then apply a 'local' force instead, would probably be easier that way.
