viewing and editing the "run command" field of a launcher

[Peter Stein <nbi wideopenwest com>]

Does anyone know how to do this? As a GNOME newbie I tried the intuitive 
thing which is right-clicking on an icon and selecting properties. Alas, 
no "run command". I have not been able to find any documentation that 
describes how to do this. Can gnome-desktop-item-edit be used for this? 
How about manual edits of configuration files, be they text or binary? TIA.