I actually tried this technique a number of years ago, when it occurred to me. Someone gave me an old print and wanted a platinum print. I copied the print to 4 x 5 using polarized light, etc, and made an 8 x 10 print on RC. I then contacted that onto lith film, developed in D-76. It worked, but the negative quality is not quite what you would get direct from film. But I do not mean to discourage you from using it. I have also tried the usual method of making a film positive and then a negative, which is a LOT of work. In addition I've tried getting my film processed by DR5 into positives and then just projecting them onto Plus X. That worked very well, but, forgive me for saying so, but I'm getting great quality from inkjet negatives and while this involves some digital technology, I see it as digital in the service of analogue.