HotTabs provides commands and matching shortcuts that will let you press:
Cltr+Num1 to go to the first pinned document tab,
Ctrl+Num2 to go to the second pinned document tab
Ctrl+Num3 to go to the third pinned document tab
etc
and
Cltr+Alt+Num1 to go to the first unpinned document tab,
Ctrl+Alt+Num2 to go to the second unpinned document tab
Ctrl+Alt+Num3 to go to the third unpinned document tab
etc
It selects tabs in the document well. Like these:
Note that there is one pinned tab on the left and three unpinned tabs following it. Ctrl+Num1 will go to the first pinned tab. Ctrl+Alt+Num1 will go to the first unpinned tab.
With the commands exposed in Tools->Options->Keyboard, you can apply your own keyboard shortcuts to these commands.