Hi Ludwin,
These can be found under your user SID in the registry (see pic below with my SID). They are stored under the 1037 entry in binary format and so they don't make sense when you look at the values.
They can also be found under Computer\HKEY_CURRENT_USER\SOFTWARE\Sybase\PowerBuilder\19.0\Shortcuts when you're logged in.
Just a caveat, I don't know whether the format has changed going from 2019R3-2703, which is what I'm running, to PB21 and so make sure you have a backup of the existing values before editing.
Would be a nice feature upon install, if the installer detects existing customized keyboard settings, ClipWindow entries etc., to ask whether to copy these to the new install.
HTH...regards,
Mark