Create my own type of attribute in diagram

Hi, i'm coding in scilab and i have some trouble to adapt the primitive type (in the diagram) to the one scilab uses.
For exemple, in scilab every Integer is in fact a Matrix (double-entry tab). So i want in my class attribut to have "Matrix" rather than simply "Integer".
And i have the same problem for an other attribute. I want to have an attribut that is a function.

So, how to i create my own type of attributes and use them in my diagram pls ?