Regular Expression to extract value from a String for a trigger?

[MarcoUK]

Hi,
is it possible to extract a value (number) from a string in a trigger?

I have this item:

Name: test_bgp_prefix
Type: SNMP agent
Key: test_bgp_prefix
SNMP OID: NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."bgpprefix"
Type of information: Text

This is my status:

snmpwalk -v 2c -c public 192.168.2.5 . | grep bgp
HOST-RESOURCES-MIB::hrSWRunName.596 = STRING: "bgp_collectd"
HOST-RESOURCES-MIB::hrSWRunName.21105 = STRING: "bgpd"
HOST-RESOURCES-MIB::hrSWRunPath.21105 = STRING: "/usr/lib/quagga/bgpd"
HOST-RESOURCES-MIB::hrSWRunParameters.596 = STRING: "/sbin/bgp_collectd"
HOST-RESOURCES-MIB::hrSWRunParameters.21115 = STRING: "--daemon zebra bgpd"
NET-SNMP-EXTEND-MIB::nsExtendCommand."bgpprefix" = STRING: /bin/check_bgp_prefix
NET-SNMP-EXTEND-MIB::nsExtendCommand."bgpstatus" = STRING: /bin/check_bgp
NET-SNMP-EXTEND-MIB::nsExtendArgs."bgpprefix" = STRING:
NET-SNMP-EXTEND-MIB::nsExtendArgs."bgpstatus" = STRING:
NET-SNMP-EXTEND-MIB::nsExtendInput."bgpprefix" = STRING:
NET-SNMP-EXTEND-MIB::nsExtendInput."bgpstatus" = STRING:
NET-SNMP-EXTEND-MIB::nsExtendCacheTime."bgpprefix" = INTEGER: 5
NET-SNMP-EXTEND-MIB::nsExtendCacheTime."bgpstatus" = INTEGER: 5
NET-SNMP-EXTEND-MIB::nsExtendExecType."bgpprefix" = INTEGER: exec(1)
NET-SNMP-EXTEND-MIB::nsExtendExecType."bgpstatus" = INTEGER: exec(1)
NET-SNMP-EXTEND-MIB::nsExtendRunType."bgpprefix" = INTEGER: run-on-read(1)
NET-SNMP-EXTEND-MIB::nsExtendRunType."bgpstatus" = INTEGER: run-on-read(1)
NET-SNMP-EXTEND-MIB::nsExtendStorage."bgpprefix" = INTEGER: permanent(4)
NET-SNMP-EXTEND-MIB::nsExtendStorage."bgpstatus" = INTEGER: permanent(4)
NET-SNMP-EXTEND-MIB::nsExtendStatus."bgpprefix" = INTEGER: active(1)
NET-SNMP-EXTEND-MIB::nsExtendStatus."bgpstatus" = INTEGER: active(1)
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."bgpprefix" = STRING: 0 OK: 2180 BGP prefixes defined
NET-SNMP-EXTEND-MIB::nsExtendOutput1Line."bgpstatus" = STRING: 0 OK: BGP Session Established
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."bgpprefix" = STRING: 0 OK: 2180 BGP prefixes defined
NET-SNMP-EXTEND-MIB::nsExtendOutputFull."bgpstatus" = STRING: 0 OK: BGP Session Established
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."bgpprefix" = INTEGER: 1
NET-SNMP-EXTEND-MIB::nsExtendOutNumLines."bgpstatus" = INTEGER: 1
NET-SNMP-EXTEND-MIB::nsExtendResult."bgpprefix" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendResult."bgpstatus" = INTEGER: 0
NET-SNMP-EXTEND-MIB::nsExtendOutLine."bgpprefix".1 = STRING: 0 OK: 2180 BGP prefixes defined
NET-SNMP-EXTEND-MIB::nsExtendOutLine."bgpstatus".1 = STRING: 0 OK: BGP Session Established

if I test my item I receive the string: 0 OK: 2180 BGP prefixes defined

IS it possible (and how can I do it) create a trigger to process this string (0 OK: 2180 BGP prefixes defined) and extract only the value 2180?

[MarcoUK]

You could add some preprocessing with regex to item, so it only saves that number, not the text.
Match: (\d+) OK: (\d+) BGP prefixes defined set output to \2 and change data type to integer. it will save just that number.

Thanks for your reply.
Could I have an example please?
I don't understand if can I set regex directly on the item (this item is an SNMP agent) or only in the trigger.