regexp help

[gokhalen]

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

M-x replace-regexp RET hello     \(......\)\1 RET hello      \1    /*
NOTE: a white space follows the \1    */


Thanks,

  -Nachiket.