Thanks Mohana, the code you mentioned is from 2009 or 2013?
I'm using a standard IT localization and I looked also at a 2009 R2 W1 and the code part is:
VATEntry."Country/Region Code" := Cust."Country/Region Code";
VATEntry."VAT Registration No." := Cust."VAT Registration No.";
Unfortunately actually I don't have access to a 2013 W1 db to complete the cross-check.