I just did a partial mash barley wine, here's the recipe. I'm not sure its a true partial, because I don't think crystal and munich give many fermentables. You could probably replace some of the DME with some pale malt or something. I don't know how to do those conversions though.
8lbs Light DME
3 lbs Crystal Malt (caramel 20)
1 1/2 lbs Munich Malt
1 1/2 oz Chocolate Malt
8 oz Dextrin
2 oz Nugget: bittering
3 oz Cascade: aromatic (possibly dry-hopped if you want)
Prime with 3/4 cup corn sugar
Pasteur Champagne Wine Yeast