The run_me_first thing is just a simple copy command. If you want you can do it yourself in a dos prompt ( wherever your PlaneShift part files are )
copy /b PSV0.2.010.Part1 + PSV0.2.010.Part2 + PSV0.2.010.Part3 + PSV0.2.010.Part4 + PSV0.2.010.Part5 PlaneShiftV0.2.010.exe