1. Place your script file(s) in AutoCAD's Search Path (add your own folder or use one of the existing, OPTIONS' commands's FILES tab, first entry at the top).
2. Start CUI command, at the Commands List portion, find the CREATE A NEW COMMAND button, click on it. Give the command a name, a description, find an icon for it if you want an icon. For the 'command' portion, use SCRIPT command and the name of your script, like this:
^C^C_SCRIPT;MyScriptNameHere
3. Move this new 'command' to the Panel or the pulldown menu you want. Adjust the button display option.
4. Click APPLY then OK to get out of CUI.
5. Use WSSAVE command to save your current active workspace.