Special Procurement key - Stock transfer

The special procurement key for stock transfer is created with special procurement U and we maintain the plant from which we want to procure.

When MRP generates Purchase requisition, PR gets created with item category U and when we convert this PR to PO, by default we get the UB document type in the ME21N transaction which is fine if both the plants are in the same company code.

But if the two plants are in different company codes, than while converting the PR to PO, every time we need to change the document type to ZIC(we use Document type ZIC for Inter-company stock transfer). This is really a burdensome especially all our bonded warehouse materials have this special procurement key (Stock transfer) and every time it is an inter-company stock transfer. As a result they need to change the document type to ZIC in the PO creation.

Is there a way for us to default to document type ZIC for those which require inter-company stock transfer ?