$re = '/(Column\s*;)\s*(;\s*DataSource=([^}]+))/m';
$str = ' { 1000000003;1;Column; ;
DataSource=Search Name }
{ 10000004;1;Column; ;
DataSource=Name 2 }
';
$subst = "$1$3$2";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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