aman2812,
You can try creating a shortcut on your system to the Quick Launch button for show desktop and then create a dock entry linked to that file.
- or -
You can copy and paste the following into a notepad file and then save to your system as 'Desktop.scf':
[Shell]
Command=2
IconFile=explorer.exe,3
[Taskbar]
Command=ToggleDesktop
Note - make sure that the 'Hide extensions for known file types' is deselected under the 'Folder Options > View tab' to allow the correct file save.
Once the file is created, test it and if it works you can create a dock entry linked to it.
As for the 'Word' issue, ObjectDock would not uninstall a program based on the deletion of a dock entry linked to the executible file. The only way this type of occurance may be conceiveable is if you had some sort of 'uninstall' utility for Word that was invoked when you interacted with the dock entry - although, I have never heard of any 'uninstall' utility for Office programs.
Did you check in the Program Files directory to see if the 'Microsoft Office' sub-directory still exists?