LSMW for Legal Control on MM02

What's the best approach to loading Legal Control defaults (on Foreign Trade export/import views) for existing materials in ECC6 system?

I need to add B - N - N on all US based materials. I looked at using LSMW with BAPI_MATERIAL_SAVEDATA but do not find the Legal countrol fields here...I am hoping that someone may have better idea.

Best Regards,

Mustafa