Restrcit Order type to a specific responsibility

HI,

I have 2 export order type ''OE_ENG_EXPORT'' and ''OE_SPR_EXPORTS''. 

I have created a responsibility ''OM Export User''.

Business want the control that order entry and maintenance of the above 2 order types should be possible from only the mentioned responsibility.
No other order types should be entered and maintained from this responsibility.

Please advice how to achieve this.