How to use c-style to comment a region?

["William Xue" <william.xue@gmail.com>]

Hi,

In cpp files, in following code, for e.g.:

ln_time_out.QuadPart = -((LONGLONG) 10 * 1000 * 1000 * 5);

I wanted to modify the second 1000 to 2000 for testing, but wanted to keep  
the orignal value for restoring it later.

after selected 1000 and pressed C-c C-c :

                 ln_time_out.QuadPart = -((LONGLONG) 10 * 1000 * // 1000
                                          * 5); // 1 second

Can it be:

                 ln_time_out.QuadPart = -((LONGLONG) 10 * 1000 * /* 1000  
*/  * 5); // 1 second

Maybe there are some settings for it, but I havn't found them.

I know that add /* -*- C -*- */ at the beginning of the file can affect  
the comment style for the whole file.
That's not my request, I only want a command or a keybinding.


Thanks!

-- 
Sincerely yours,
William