Modelica Variable size connectors

Question

I want to do Monte Carlo simulation with a model. This model has some external functions linked to a library that reads its inputs from a file. I have been recently experimenting with ".mos" files to run the same model over and over. With external files it is easy to change them and re-simulate the model using the mos file (even in parallel). Yet I was unable to change the internal parameters of the model in the mos script. I have done many experiments and been looking for the answer for some time now. I wonder what is the correct syntax for changing the parameters of the model inside a simple .mos file like the one below.

cd(<working directory>);
loadFile(<address of the package that also loads the OpenModelica>);
simulate(<model>, stopTime=<...>, numberOfIntervals=<...>);
quit();

For instance, lets say the model has a parameter param and a submodel sub with the parameter sub_param. How can I change param and sub_param inside the mos file.