Thirst, I became sad by your answer, but the links you mentioned gave me a way to overcome the problem. And I became happy again. I changed all the "eval" statements to "feval" which supposed to be a proper alternative.
Unfortunately I stuck into a "previously accessible file "MyFun_Kees" is now inaccessible"-error. Then, I found out that this had to be with the use of "addpath" in a deployed/compiled version. However, removing the "addpath" gives an "Undefined function or variable" problem.
This brings me in a vicious circle (Please, help me out?!).
How can I tell Matlab to look into a folder for files/functions to execute/call?