I’m guessing you don’t have a copy of PiaPro Studio which can export as vsqx. I recently heard of a file converter for vocal synth files called
LibreSVIP, but I’ve never used it myself and don’t know how to use it or if it converts that file type. You can install the trial of
Miku v4x, Miku v4 eng, or Luka v4x, which come with a PiaPro Studio v4x trial, and export a vsqx or midi from there. If use the trial you will use up your trial of that Vocaloid voicebank on your computer, so you might want to play around with the software while it’s installed. (Miku’s trials are for 39 days and Luka’s is two weeks)