Here's a fairly comprehensive (though by no means complete) list of banjo tunings:
It includes such tunings as dADAD, aADAD, aDAAD, aDADF#, and others. (in written banjo tunings, the first lower case letter is the short drone string)
The real question however is what you want to do by tuning a banjo to D and A notes. What we think of as "dulcimer tunings" are really just notes. Usually a tuning is used to achieve a specific purpose. It enables us to play a tune more easily, or to play it in a certain way or with certain fingering positions.
You haven't told us what your situation or your goals are, so I'm making assumptions here- As a longtime player of both mtn dulcimers and banjos (and I'm really more a banjo player than dulcimer player), my personal advice would be this- play your dulcimer like a dulcimer. If you want your dulcimer to have a tone like a banjo, get a dulcimer with a banjo head on it. Learn to play and (initially) tune your banjo as a banjo, rather than trying to make it imitate a dulcimer. Banjos are designed to be played most easily like banjos, and learning to play a 5string oldtime banjo is not all that hard, after getting past the first little learning hump of unfamiliar right hand motions. IMHO if you're tuning a banjo like a dulcimer in order to try to make it easier to learn to play (if you're a dulcimer player), you are doing yourself no favors. It might make the first week or two seem easier, but it will make playing the banjo harder and way more limited later on, plus most banjo learning material will then be useless to you as well.
If I've made incorrect assumptions, then forget all this. lolol!
Those irritated by grain of sand best avoid beach.
-Strumelia proverb c.1990