Mixing cooking chocolate with normal chocolate
Divi, I would try a sample melting of the two chocolates - do this very slowly in a double boiler or if you are super-careful, in a microwave - to see how the two chocolates react to being mixed once melted.

If they mix adequately, drop the test mix on a piece of wax paper and let it cool to see how the re-hardened mixture firms up.  Based on your experiment, you should have a better idea of what to expect with the two dissimilar chocolates.  (rumtscho has a good point that without knowing exactly what the two chocolates are, it's hard to give an answer.)