A quick and easy to take a image and convert it to g-code with UltimateCNC.
All GUI buttons can be customized. But, by default, the commands executed when click on buttons ("Go Home", "Go Z up") of UltimateCNC are using work coordinates, it means, when you click on "Go Home" the GUI execute G00 Z5; G00 X0 Y0; G00 Z0. If you want change it, to use machine coordinates or whatever, you can. For example, maybe if you have switch limits installed, you want execute on click in "Go Home" as G53 G00 Z0; G53 G00 X0 Y0;
With Ultimate CNC you can create your own buttons that it will execute your own commands (macros).