How can I write a code for a lunar lander with variable mass and thrust in order to land with a velocity of near zero?

Hi, I'm looking for some help/tips in how to write a code to plot the velocity against time for a Lunar Module starting at a certain height and velocity (just in the vertical direction) in the moons atmosphere., with a variable thrust which corresponds to how much fuel is being used hence the weight of the module. The change in mass = (Thrust maxthrottle)/(Isp9.81) where throttle is between 0 and 1 and the thrust max and Isp are known. The module needs to landing with a velocity below 5m/s. Thank you for any help

[per isakson]

Did you search the File Exchange? See Moon Lander Matlab Game-Example of getting keypressed, by Héctor Corte