There are certainly Exakta-to-LTM adapters out there (Topcon SLRs, until the mid 70's or so, had Exakta mounts). You would, however, lose infinity focus and not be able to use rangefinder focussing.
The Topcor lenses for their RE/Super D cameras are all mighty fine, although the range is somewhat lacking in the speed department, a result of the small Exakta mount (they did manage to push out the first f2.8 300mm lens, however). Anyway, xayraa33's advice is sound -- get a Topcon SLR for your lens.
Cheers,
David