Installed cnc-draw as others have mention from https://github.com/FunkyFr3sh/cnc-ddraw, extracted this into the games root install directory under steam.

Edit SUN.ini and add under [Video] AllowHiResModes=yes ScreenWidth=1920 ScreenHeight=1080

Obviously change to what resolution you need, thats it!

NOTE: I tried following the more advanced instructions from the other posters here but I found that as soon as you touch DDrawCompat.ini this will cause steam to redownload and patch the game which blows away any manual edits in DDrawCompat.ini and the SUN.ini file.

The game does work without tinkering but you are stuck with small resolution and scroll speed is slow/laggy