Creating Vendor Documents - Dealing with Blocks

[DarcyMorse]

We have a requirement to block vendors for payments if they haven't returned Legal Documents (need to be filed every so many years depending on the scenario).

Based on the comment above, we have 2 Scenarios:

1. We have an interface that is creating vendor documents.  We want to be able to create the documents, but not pay them thru F110. 

2. We have Vendors that work thru another vendor for direct deliveries. Once the interface in the previous step creates the vendor document, we want to be able to clear that entry thru FM POSTING_INTERFACE_CLEARING, but if they have items that need to be paid to them, we don't want those invoices to be paid thru F110. 

We tried using an A in Payment Block.  This allows the documents to be created, but can't be cleared thru the POSTING_INTERFACE_CLEARING FM.

Is there another option we can use in BP to accomplish the scenarios above?