Search and Replace using regular expression. Sample request:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 
xmlns:ws="http://ws.xservices.brutex.net">
   <soapenv:Header/>
   <soapenv:Body>
      <ws:replaceRegEx>
         <string>Hallo Welt</string>
         <search>W.*</search>
         <replace>Brian</replace>
         <regexflags>ig</regexflags>
      </ws:replaceRegEx>
   </soapenv:Body>
</soapenv:Envelope>

Sample response:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body>
      <ns2:replaceRegExResponse xmlns:ns2="http://ws.xservices.brutex.net">
         <return>
            <string>Hallo Brian</string>
            <count>1</count>
         </return>
      </ns2:replaceRegExResponse>
   </soap:Body>
</soap:Envelope>

Allowed regexflags are case-insensitive (i) and global search (g).