Anybody got any experience with Matlab/Simulink?

Here's the deal.

At work we are working on a way to interface a Garmin GNC 250XL GPS with a laptop and have it read data into Matlab. Currently we only have Matlab 5.3 so we are having to use Simulink as a patch to interface Matlab to the serial port and from there to the GPS.

Here's where the problem lies. We havn't been able to figure out yet how to program an interface between the GPS and Simulink. Does anybody have any clue how this could be done or where I could find some Simulink code that could do this?

Any help is appreciated.

You might want to consider using C or C++ to write the interface, if you have any experience with it. You can then use Matlab's mex function to compile and run the C code in Matlab.

Don't know how to do it in Simulink, though, as I've never worked with it.