The item is called "SearchUrl"
They are saved in the registry, along with a list of translations for special characters.
An example, using your request:
Create a .reg
file
Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\SearchUrl\kb] @="http://go.microsoft.com/fwlink/?LinkID=%s" ":"="%3A"
This will register the keyword kb - the %s is the placeholder for the string you supply.
It also knows that when you type a :
in the string that it should be substituted by %3A
in the URL to ensure it is passed correctly.
Other common substitutions could include:
" "="+" " "="%20" "#"="%23" "&"="%26" "?"="%3F" "+"="%2B" "="="%3D"
Note you can only have one definition for each character, so in the above list, you would have to decide if a space should be translated to %20 or +
If you wanted other shortcuts, you could add them in place of the kb, and produce a list of special shortcuts - this site has several you can choose from. (go, find and ? have special meaning, so cannot be used)
To actually use the shortcut, use the address bar (shortcut is ALT+D ) and type your text in there, e.g. kb 198279
takes you to Managing Exchange Server 2007: How to Configure Storage Quotas for a Mailbox Database