Is there a way to configure dosbox so that Dungeon Keeper runs at 60 fps?

Dungeon Keeper does 20-30 game steps per second. If you want the game to render 60 frames which look different (are not exactly the same), you have to change game turns per second first.

To conclude:
- you have to influence the game, not DosBox
- there's a "-fps <N>" command line parameter in DK.