updating a nested parametric sweep

Hi
I use nested parametric sweep and once in a while after the model has been solved, I would like to add one or two additional values to my parameters to fill the gap between them or increase the range of them. It is also desirable to have the results in the same file so that it could be analyzed, stored and recovered easily. Since some models would take a long time to solve for all the parametric sweeps, I was wondering would it be possible to somehow solve only for the new values and have the parametric solution updated so that it incorporates new parameters as well?
Thanks,