the best thing you could use is:
phent_addvelcentral(my,vector(strokepwr,0,0));
i think
also you could use

phent_addcentralforce ( ENTITY*, VECTOR* vForce );
phent_addforceglobal (ENTITY* entity,VECTOR* vForce,VECTOR* vPos );
phent_addforcelocal (ENTITY* entity,VECTOR* vForce,VECTOR* vPos );
phent_addtorqueglobal ( entity, vecTorque );
phent_addvellocal
phent_addvelglobal