My modelling chocolate seems to dry even after working it. My question is this can I melt it again and add a little more corn syrup?

I stick it in the microwave for a few seconds and just start working it .. the heat from the microwave and then my hands seems to work.

"Dry" modeling chocolate usually means that the chocolate was overheated or seized when making it.

Adding more corn syrup won't fix this--actually, nothing that I know of will fix this to the point of getting a nice product.

Sorry.
Rae