Creating a String/Expression for Blocked Phrases Content Filters

Perhaps someone can help me out?  I am trying to create a sting or expression in Puremessage that scans outgoing mail for account number information.  If the account numbers are 9 consecutive digits how would I do this?  The manual provides the following example.

Filtering blocked phrases - regular expressions

To define a regular expression as a blocked phrase:

1. In the console tree, click

Configuration | Transport (SMTP) Scanning Policy, and then click

Content

2. In the

internal messages are green and display

3. Under

4. Under

5. On the

6. Click in the

.Content filtering dialog box, ensure that the status icons for inbound, outbound andON.Internal messages, select the On blocked phrase check box.Internal messages | On blocked phrase, click Define.Regular expression tab, click Add.Phrase box and type the following regular expression:

[0-9]\{4\} ?[0-9]\{4\} ?[0-9]\{4\} ?[0-9]\{4\}

This expression will match credit card numbers in both "1234 1234 1234 1234" and

"1234123412341234" formats.

7. Make sure that the Attachment check box is selected.

Any ideas?