In WSM it's possible to create models that call external function in DLLs. I've been using a modelica wrapper to the oscpack library (http://www.rossbencina.com/code/oscpack) that allows sending and receiving simple OSC messages. This makes it possible to communicate with music applications that implement OSC. I've been using it to send input signals from an iPhone using TouchOsc.

Most interesting - thanks for the tip.