gokhalen@gmail.com wrote:
> Hi,
> 
> I needed to replace lines matching the following pattern
> 
> "hello      123456123456"
> 
> with
> 
> "hello      123456 123456"
> 
> I used
> 
> M-x replace-regexp RET hello      ...... RET \&                      /
> * NOTE: a white space follows the \&  */
> 
> To do this.
> 
> I was wondering how I would do this with the \d construct. That is how
> would I do this along the lines of

I'm not sure, but I think you want this:

M-x replace-regexp
\([0-9][0-9][0-9][0-9][0-9][0-9]\)\([0-9][0-9][0-9][0-9][0-9][0-9]\) RET
    \1 \2 RET

There may be some way to avoid repeating the [0-9] but I couldn't figure
that out.

Matthew Flaschen