Total Commander

We have these:

CTRL+< Jump to the root directory (most European keyboards)
CTRL+\ Jump to the root directory (US keyboard)

But some people use US keyboard with European mapping (like me). Both characters (< and \) are accessible only by a hotkey and TCMD does not recognize CTRL + hotkey. Can you add the third option? Something like ctrl + *, which is not associated to anything yet.

Thanks!

Configuration>misc.

And then redefine the keyboard hotkey for
cm_GoToRoot

and TCMD does not recognize CTRL + hotkey

How? TC recognizes any hotkey, which will be specified in TC options. Go to Configuration->Misc. and define any hotkey to cm_GoToRoot command.
or
Add this line in wincmd.ini file in [Shortcuts] section:
C+*=cm_GoToRoot