I am not quite sure what you want. Is it the Quick Launch bar, or the Quick Launch (show desktop) command on the Quick Launch bar?
As far as I know the Quick Launch bar is not a file, but an explorer command called "Quick Launch". IE knows that if shortcuts are placed in a specific folder, they are supposed to be on the quick launch bar on your desktop. The shortcut is as follows: "C:\WINDOWS\Application Data\Microsoft\Internet Explorer\Quick Launch", and as can be seen, it is not linked to an executable, but a folder. As long as you have a working IE, and you place your shortcuts in the the "Quick Launch" folder, the shortcuts should appear in the quick launch bar...
There is also a file in the Quick Launch folder, called "Show Desktop", but IE should place it there by itself. I have not sent mine, because I dunno if it works with XP (I am using ME, and I do not know if there is a difference between the 98 and ME file). If you have deleted it, it should be pretty easy to retrieve it manually from the windows *.cab files, with the "extract" command (provided that M$ have not removed this from the XP package).
I hope this helps. If it doesn't, or you want the ME file, then you know the drill...
It's only after we've lost everything, that we are free to do anything.