Simply copying the directory will not get Mach3 to work. The driver must be installed.
So if you only need to cut 15 lines of GCode, you can just download the latest version of Mach3, install it, then copy over your *.XML files, which holds the settings for your CNC machine and it should be able to cut your job.
My registered version also has a Mach3Lic.dat file with the latest version, you can copy that over as well, it should still work, but I cannot be sure.
Hope this helps.