Combining/extending monte carlo simulation results

I'm using ADE Assembler (IC6.1.7-64b.500.17).

I ran a monte carlo simulation and now I would like to extend the number of runs.

The way to go is probably to use the same seed, increase the 'first point' number with (at least) the number of simulations that already have been performed and run the simulation again.

But I'm not sure how to combine both results as to obtain a single distribution.