How can I pass a character function to the input of another function?

Hello! I had the following problem. I need to make it so that I can enter a symbolic function, which will later be used:

F = s.*exp(s.*t);

and I need to use this function as an input to another example:

function Example(Aval, Bval, Cval ,Dval, Nval, Mval, F)

hs = (Bval - Aval)/(Nval - 1);
ht = (Dval - Cval)/(Mval - 1); 
Sval = (Aval:hs:Bval)';
Tval = (Cval:ht:Dval)';

Amat = zeros(Mval,Nval);
hs = (Tval(Nval) - Tval(1))/(Nval - 1);
for i=1:Mval,
    Amat(i,1) = F(Sval(i),Tval(1))/2;          
    for j=2:(Nval-1),
       Amat(i,j) = F(Sval(i),Tval(j)); 
    end
    Amat(i,Nval) = F(Sval(i),Tval(Nval))/2; 
end
Amat = hs*Amat;
end;

The problem is that I need to do this for codegen. How can I do it?

myhelp = {ones(1,1,'double'),ones(1,1,'double'),ones(1,1,'double'),ones(1,1,'double'),ones(1,1,'double'),ones(1,1,'double'), ???????????};
codegen Example.m -args myHelp