Exporting deduped information
You will not be able to do that with the GUI since it lists the matched pairs but does not allow to export it in a configurable way.

Your best bet will be to use the API (that means programming in PHP), and specifically the entity Contact, action duplicatecheck. Here is a sample code:

$result = civicrm_api3('Contact', 'duplicatecheck', array(
  'sequential' =&gt; 1,
  'dedupe_rule_id' =&gt; 4,
));


This will return a list of matched contact pairs with the dedupe rule 4.