Need to write a matlab function for set of files and interconnection of all.

I have a matlab calculation m.files
1. HB_Converter
2. Ferrites
3. Metglas
4.pow_iron

Some can write a function which satisfices the code in HB_converter. The function name should be cores. The cores function wll be called from HB_converter, and the cores function checks the core types according to the input by user prompt for the 2-4 core meterials.