I need to invoke a keyboard shortcut from within an AppleScript code, later to be used as a startup item (i.e. the alternative to having to press something at every log in).
I get the impression that what you're trying to do is a copy command (i.e., ⌘C)—am I right?
Here's an example from one of my scripts:
tell application "System Events" tell application "Microsoft Entourage" to activate tell menu "Edit" of menu bar item "Edit" of menu bar 1 of process "Microsoft Entourage" click menu item "Select All" click menu item "Copy" end tell key code 123 end tell
That is, I script the menu command instead of scripting shortcuts.
You might also take a look and see if you have
/Library/Scripts/UI Element Scripts/Key Down-Up.applescript, which should give you alternate ideas of how to emulate keyboard actions.
And of course, there are a lot of examples in
~/Library/Scripts/, many of which are worth a look in general.