Yes, if you use a regular expression like:
\b(\d{4}[ -]?){4}\b
that should find any credit card numbers in a file. If you have a look on the Internet you'll see more elaborate regexs which eliminate some of the false positives.
If you need to export anything found have a look at this QA article:
//qa.mythicsoft.com/10328/finding-exporting-email-addresses-credit-numbers-group-files
