Pablo,

How much does it hurt to actually say to collect the first 19 interfaces

If the pattern matching is the same as used in rulesets, then the following
should give you 19 interfaces

^1*[1-9]$

Let me know if this helps.

To get the first 39 should be    ^[1-3]*[1-9]$

Kind regards,
Stephen Hochstetler              shochste AT us.ibm DOT com
International Technical Support Organization  - Austin
Office - 512-436-8564                      FAX - 512-436-8701

ITSO redbooks at  http://www.redbooks.ibm.com