MDG - S/C Security role based on account group

Folks,

I have a requirement wherein I have to restrict users based on security role from editing certain account groups. So if user is authorized to delete vendor account group A, plan is to create a security role with that account group.

My question is how to accomplish this, as MDG-S creates Business Partner and then vendor. So how do customize the security role SAP_MDGS_REQ_04? Is security role based restriction possible in MDG? What is alternate approach if security doesnot work? Any pointers will be greatly appreciated.

Thanks,

Kartik.