XML : XML request with partial of key word

I have requirement of selecting subset of data from a collection using a part of a key word

Assume that I have a collection consist of following entries,

   6876   42897   72356   42    

When I provide a search string as "42" following should be filtered;

  42897  42    

This is my xml request which returns correct results if I write the exact key word here is "42"

  <soapenv:Envelope xmlns:soapenv="http://example.com/soap/envelope/"   xmlns:prod="http://example.services.com">   <soapenv:Header/>     <soapenv:Body>       <prod:productBySKURequest>       <prod:key>42</prod:key>     </prod:productBySKURequest>   </soapenv:Body>  </soapenv:Envelope>