Absolutely! As long as the model you want to run was built in a Model Developer Edition of ExtendSim, you will be able to run it in Trial mode. Just know that their model will open with a "Trial version" watermark behind the model on its worksheet in your Trial version.

Please make sure you are using the same ExtendSim package the model developer used to create the model. For example, if your colleague built a model using ExtendSim Pro, you would need to be using the Trial version of ExtendSim Pro, not DE or CP as they may not have the proper components to run the model.