Create a transfer order with an Empty Vendor number

Question

I have a requirement where I have to create a transfer order with empty vendor.

The scenario is:

• The client wants to maintain its in-house stock, and in-house stock does not have any Special Stock no. (Vendor) in table LQUA.
• If this stock is available then the transfer order should be created with LTAP-SONUM = Empty.

I am trying the login in EXIT: EXIT_SAPLMDBF_002

I am currently applying C_XT434P-BPRIO = Empty and C_XT434P-LIFNR = Empty in my EXIT after the stock validation.

But still SAP standard re-calculate the Vendor and assigns it an Consignment Vendor.

But if I assign an consignment vendor in the EXIT i.e. C_XT434P-BPRIO = 'K' and C_XT434P-LIFNR = Consignment Vendor no., then Transfer order is created with the vendor I have assigned.

Please help me in creating Transfer order with Empty Vendor.