I've blended wine into beer with great results. Normally I use it for sour beer, but it will work for 'clean' beers as well.
I like the idea of a big, English barleywine with low carbonation (or still). You could blend in some decent commercial port to evoke those familiar flavors while still retaining the beer's character.
English Barleywine is a nice foil for port because it has alcohol intensity that isn't balanced by roast, bitterness, and/or carbonation. Both barleywine and port benefit from a stay in oak and/or graceful aging.
I would try blends in the glass first. You bring a few commercial barleywines, your buddy brings a bottle of port. I've never blended port and beer, but I would start by assuming it won't take much port (<10%). 50/50 may be the answer, or this could be a terrible idea altogether. You never know until you get it in the glass.