Hyperlynx scope only support 2 cursors, you have to use Ezwave for numerious cursors. So you can save the wave and load it to Ezwave for adding cursors. Ezwave is included in Hyperlynx Analog and you can invoke it by keyin "ezwave" command. If you don't have Hyperlynx Analog installed, try to install it and invoke Ezwave from the command line.
A good news for Hyperynx user is that Hyperynx 9.0 have adopted Ezwave, so Hyperlynx user can view large wave data very fast and process waveform easyly