Remember your own comment in the original posting: XP (and 2003) is going to lose its updates next April and hence will be very dangerous online.
One solution I've mentioned elsewhere is: run an XP machine for non-internet use (set the firewall for local network only) and use linux anything online. This may be a better solition than trying to run "custom" software under wine or similar. There is a list of known working apps at (I think) winehq but not everything that works is listed there.
Also remember that running XP from wine or any other vmware MAY still render the computer vulnerable to online exploits.
You may well find Kate or Geany to be a better option that notepad. Downside of Kate is that it's a KDE tool but it is a good one with a lot of extras, more equivalent to the far better MS app textpad than notepad. Geany is (I think) a gnome equivalent to Kate.