If you have not copied your files to proper folder, then it is clear why it do not work for you.
USER_PATH is a system variable that can be used to access the user partition on the system to store data. Instead of using a drive letter, USER_PATH can be used to access the user partition on all target systems (including ARsim) regardless of the actual partitioning. In ARsim, the directory corresponding to USER_PATH is found at \USER.
So in short, folder for USER_PATH accessed by ArSim you can find in Temp folder in your project.