Stereo Analog VU Meter - RMS - Version 1.51 winamp plug-inor maybe a stand-alone windows VU program.
I have never seen volume level meters in RR, but the easiest way to do it would be to use a winamp visualization in the designated area. Searching Winamp, I found these:
Peak v1.0 - Peak meter visualization plugin
Osciloscope and VU meter - Osciloscope, VU Meter, spectrum analyser and spectrum meter