Function call

Not sure this is what you are asking for, but you can compile a .mos file as package. Then you can use the functions from that package in other .mos files by importing the package via "uses" or "import". See the documentation for further details.

Several examples of Mosel packages (=Mosel libraries implemented with Mosel) can be found in the Mosel User Guide, see Packages (fico.com)

If your question relates to how to run a Mosel model from another model, you will find an introductory example in the Mosel User Guide: Language extensions (fico.com) and a more in-depth discussion with a collection of advanced examples in the Whitepaper 'Multiple models and parallel solving with Mosel'.