setsfx = bj_lastCreatedEffect//or ever better//eithersetsfx = AddSpecialEffect("path",x_coordinate,y_coordinate)
//orsetsfx = AddSpecialEffectLoc("path",loc_point_etc)
//orsetsfx = AddSpecialEffectTarget("path",doodad_unit_whatever,"origin or any attchemnt point")
//depending what you need