The full cubase 7 has it integrated into the mixer, unfortunately your Artist version has not.
Slm was made for cubase 6.
Try Voxengo SPAN, it has a metering suite build-in and it is free.
Or try downloading the TT meter from Tischmeyer, it should be somewhere on the net.
I think your best change is via reading this blog
Edit: Or else you can try to do what other posters have done. Don’t know if that will work.