According to Microsoft, only shortcuts to .exe files are allowed to go on the left-hand-side of the Start Menu. Is there any way around this? I’d like it to be possible to put shortcuts to .com and .bat files there.
Can’t you just right click on Start>Explore All Users. Once you are there just copy/paste your .com or .bat in there? Is that what you mean?
I got it to work for batch files (either ending in .bat or .cmd):
a. Right-click on the short-cut in the Start Menu.
b. Select the short-cut tab at the top.
c. Modify the target field of your batch file’s short-cut by adding cmd.exe /c to the front.
All this does is launch a command window that in turn launches your batch file. Since the command window is an .exe, XP adds it to the LRU list, but it still uses the shortcut’s name.
You sound pretty computer savy, but I can provide more details if you would like. I assume this would work for .com files too.
Like so many scarcely-documented features, the answer to this is yes and no.
Yes, you can put non .exe shortcuts on the left side of the start menu.
No, they can’t be in the lower-left portion.
Clear as mud? 
The lower-left section, is, I believe, called an Intellimenu in Redmond-speak. It is an “intelligent” menu in that it displays the last six applications you’ve used. Really, it’s just another form of a History menu. If you want to change it from six to something else, right-click the start button, select Properties, Start Menu tab, Customize… and right in the middle of the window will be “Number of programs on Start menu:” You can set it anywhere from 0 to 30. The only .com executables that come with Windows now are old DOS applications, included for their apparent historical curiosity. So, to Windows, the only executable files are .exe - types bat, com, scr and pif need not apply.
However… The upper-left section is where you can drag shortcuts to the Start button, hover for a moment, and have the menu open, and drop your shortcut on that area.
One half-witted trick you can do with the Intellimenu portion is “pin” an application - right-click an application that you always want available there and select Pin to Start Menu, which will make it move to the upper portion. How this is better than just dragging a shortcut eludes me. To remove the “pinned” items, right-click and Unpin.