Many thanks - indeed I thought it was C-u <number> 
thanks for setting me straight!

On Fri, Jan 2, 2009 at 4:32 PM, Juanma Barranquero <lekktu@gmail.com> wrote:
> Shouldn't it be C-1-6 C-u 7?

Keeping Ctrl down and pressing 1-6-u works too.

   Juanma