How to change base workspace variable using m-stript?

I have a m-script for loading some simulink.signal and simulink.parameter variables into the base workspace, and then I would like to modify some of its properties such as the code generation options field.

The problem I have is, I'm using the function whos to get the list of the variables in the base workspace, but for each element of that list, I only have the name of the variable as a string, and I don't know how to convert that into a object handle sort of thing, can anyone help?