Posting block vs Purchasing Block for External Business Partner

Dear colleagues

We use SRM 7.02 ECS

I have a problem with the replication of a vendor that has Posting Block

In ERP if vendor has Posting Block , ERP allows you to create requisitions or PO's but doesn't allow to post invoices to that vendor code

This is ok for me as the Purchasing block is not flagged

My problem is that i want to have same behavior as in SRM , so the posting block is flagged ( invoice posting in my understanding and as ERP behavior ) , but i should be able to have , see and use this vendor in SRM for SC -> PO -> CONF

Supplier is visible in BP

Supplier has entry in BUT000

But supplier is not visible in SRM Administration - Supplier

Is not visible in search window when you search by vendor code

But if you manually type in the vendor code and try to assign, then SRM is showing error: Supplier not permitted

Any recommendation how to achieve this ?