Is this a general question or do you want to run another program via the taskbar shortcut in place of Windows Task Manager? If it is the latter then many of the available alternatives allow you to replace windows own Task Manager, via their own settings, and then the Taskbar shortcut would open your chosen replacement. System Explorer
Main > Options > General > check the box- Set System Explorer As Main Task Manager Process Explorer
From the menu bar select Options and select 'Replace Task Manager' from the drop-down menu
There are others...