Dungeon crawling kind of sucks for bow and arrow users, anyways, so I think your friend will have to just get used to it. No need to PrC if you don't need to. I'd try this:
Ranger 2 / Fighter 18
Point Blank Shot, Precise Shot, Rapid Shot (is free), Manyshot, Improved Precise Shot, Woodland Archer, Weapon Focus, Greater Weapon Focus, Weapon Spec, Greater Weapon Spec, Defensive Archery, Piercing Shot (one of my favorites), Ranged Weapon Mastery, Far Shot (I think that if there is any concern about dungeon crawling, delay this feat), Weapon Supremacy (is hilarious)