Exporting to Step using RhinoApp.RunScript nothing happens

I have a basic polysurface that I want to export to Step. When I run the script nothing seems to happen, but no errors are thrown. Could anyone shed some light on this.

Thanks !

import Eto
import Rhino
import rhinoscriptsyntax as rs
import scriptcontext

out_file = "AG.step"

obj_list = rs.AllObjects()

for o in obj_list:
    print rs.ObjectType(o)
    Rhino.RhinoApp.RunScript("-_Export " + out_file + " Schema=AP214AutomotiveDesign " + " ExportParameterSpaceCurves=No" + " LetImportingApplicationSetColorForBlackObjects=Yes" +" Enter", False)