Hi,
To mimic the while loop you can use the "While iterator subsytem" described here. I have attached my model of the subsytem which seems to be very complex but the logic is quite simple and described in the model itself. You will notice that stop time is set to 0, this is because the while iterator subsystem is configured to run while the condition is true or till the max number of iterations is exceeded so we can get the required answer in the first time step itself. I am sure the model could be made simpler so have a look to understand my implementation and make changes according to your needs.
Hope this helps.
