Hi,

1. Click Tools menu  Customize  Edit Command Aliases (PGP). (ALIASEDIT command) 
2. TextEdit application will open with acadlt.pgp file loaded, in the text editor, add your new command aliases to the bottom of the file. Save the PGP file after you make the desired edits. 
3. In AutoCAD or the AutoCAD-based product, click Tools menu  Customize  Reload Command Aliases (PGP)

Now test your custom command aliases.

Maxim