Importing elements of a structure from MATLAB workspace based on a user given constant in Simulink.

Hi,

I have various structures in my MATLAB workspace. Each of them consists of 6 fields of 'double' type. I want to pass one of these structures to a function in simulink based on what value is selected for a particular constant.

Example:

I have two structures labelled ABC and DEF. ABC has 6 fields called ABC.a, ABC.b, ABC.c, ABC.d, ABC.e and ABC.f. Same goes for DEF.

Now if user inputs constant 1 in a user input block in simulink, I want to pass the structure 'ABC' to a matlabfunciton block in simulink otherwise i wanna pass structure 'DEF'.

What would be an efficient way to do it?