title: Regex for finding message identifiers
body: <p>Please a regex expert help me out I totally done for with this.</p>
  <p>Here is an example from the text:</p>
  <pre><code>BO_ 2617247491 Msg_06: 8 DataloggerConfiguration
   SG_ DL_error_active_3 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_active_2 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_active_1 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_active_0 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_5 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_4 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_3 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_2 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_1 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_0 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
  
  BO_ 2617248003 Msg_08: 8 DataloggerConfiguration
   SG_ DL_gl_err_rea : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_gl_err_rea_hi : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
  
  BO_ 617247747 Msg_07: 8 DataloggerConfiguration
   SG_ DL_error_code_11 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_10 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_6 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_di_nr_of_active_entries : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_9 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_8 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
   SG_ DL_error_code_7 : 11|8@1+ (1,0) [0|1111] &quot;[-]&quot; Vector__XXX
  </code></pre>
  <p>I am trying to find those meassage identifiers (10 digit nums. after the BO_), which are followed by in it anywhere a DL_error_code.</p>
  <p>As far as I got is this regex:</p>
  <pre class="lang-cs prettyprint-override"><code>(?&lt;!VAL_\s)\d{10}(?=.*\n*.*DL_error_code)
  </code></pre>