I searched mightily how to get duplicate icons in the taskbar. If you want to try it is simple:
Go to Program Files (or Programs Files (x86): C:\Program Files\GPSoftware\Directory Opus, copy & paste dopus.exe. Now you have dopus - Copy.exe. Drag dopus - Copy.exe to taskbar and it will pin itself.
We advise against renaming or copying the Opus exe and dll files as it can cause problems, since they look for each other and expect to have particular names. Things may also go wrong when you update the program.
What are you aiming to do with the second pinned icon? The only use I can think of is it gives you a taskbar button that will always open a new window, even if other windows are already open. There are other ways to do that, if that's what it's for. Maybe there's another use which I haven't thought of?
Or has something gone wrong with the main pinned copy? Usually, unpinning it, then launching the program and re-pinning it will fix that.