When I import a STEP file, SolidWorks creates a large number of .sldprt files.  That is fine, but I would like to control the common part of the filename for the files that are created.  Right now, I get product-name_1.sldprt, product-name_2.sldprt, product-name_3.sldprt, et cetera.  How can I have SolidWorks instead create mystring_1.sldprt, mystring_2.sldprt, mystring_3.sldprt, et cetera?