$re = '/<EventTypeCode csd-code=\"(?<myEventTypeCode>\w{3}\-\d{2})\"/s';
$str = ' <85>1 2020-03-22T18:00:44.389Z hcoxadepdtest01-app06-icwpxs01.net.swisscom-health.it icw-chr 48261 IHE+RFC-3881 - <?xml version="1.0" encoding="UTF-8"?>
<AuditMessage>
<EventIdentification EventActionCode="E" EventDateTime="2020-03-22T18:00:44.388Z" EventOutcomeIndicator="0">
<EventID csd-code="110112" codeSystemName="DCM" originalText="Query" />
<EventTypeCode csd-code="ITI-18" codeSystemName="IHE Transactions" originalText="Registry Stored Query" />
</EventIdentification>
<ActiveParticipant UserID="2f66e56b-7d4e-4fb3-86ad-ba53a2208b5f" AlternativeUserID="48261" UserName="" UserIsRequestor="true" NetworkAccessPointID="10.1.44.2" NetworkAccessPointTypeCode="2">
<RoleIDCode csd-code="110153" codeSystemName="DCM" originalText="Source Role ID" />
</ActiveParticipant>
<ActiveParticipant UserID="1111111111139" UserName="Gabriela Brunner-Mühlethaler" UserIsRequestor="true">
<RoleIDCode csd-code="HCP" codeSystemName="2.16.756.5.30.1.127.3.10.6" originalText="Behandelnde(r)" />
</ActiveParticipant>
<ActiveParticipant UserID="Internal" UserIsRequestor="false">
<RoleIDCode csd-code="110152" codeSystemName="DCM" originalText="Destination Role ID" />
</ActiveParticipant>
<AuditSourceIdentification AuditEnterpriseSiteID="2.16.756.5.30.1.194" AuditSourceID="hcoxadepdtest01-app06-icwpxs01">
<AuditSourceTypeCode csd-code="9" codeSystemName="DCM" originalText="Other" />
</AuditSourceIdentification>
<ParticipantObjectIdentification ParticipantObjectID="304909^^^&2.16.756.5.30.1.194.3.1.1&ISO" ParticipantObjectTypeCode="1" ParticipantObjectTypeCodeRole="1">
<ParticipantObjectIDTypeCode csd-code="2" codeSystemName="RFC-3881" originalText="Patient Number" />
</ParticipantObjectIdentification>
<ParticipantObjectIdentification ParticipantObjectID="urn:uuid:10b545ea-725c-446d-9b95-8aeb444eddf3" ParticipantObjectTypeCode="2" ParticipantObjectTypeCodeRole="24">
<ParticipantObjectIDTypeCode csd-code="ITI-18" codeSystemName="IHE Transactions" originalText="Registry Stored Query" />
<ParticipantObjectQuery>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</ParticipantObjectQuery>
<ParticipantObjectDetail type="QueryEncoding" value="VVRGLTg=" />
<ParticipantObjectDetail type="urn:ihe:iti:xca:2010:homeCommunityId" value="Mi4xNi43NTYuNS4zMC4xLjE5NA==" />
</ParticipantObjectIdentification>
</AuditMessage>
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php