MATLAB: Stateflow array of buses

Hello,
i have working Matlab code with a section of it like this:
coefs(1).c = a1;coefs(2).c = a2;coefs(3).c = a3;
where
a1, a2, a3
are 2×6 arrays.
Now I wanted to implement this in a stateflow diagramm but I can't figure out how to define the bus for stateflow.
the corresponding stateflow code is like the above code and the datatyp of the variable "coefs" is "COEFS".
Valentin

coefs_ = repmat(struct('c',zeros(2,6)),1,3);