title: Substring in middle of names
body: <p>My table contain column [File] with names of files</p>
  <p>I have files like :</p>
  <p>U_1456789_<strong>23456789</strong>_File1_automaticrepair</p>
  <p>U_3456789_<strong>3456789</strong>_File2_jumpjump</p>
  <p>B_1134_<strong>445673</strong>_File3_plane</p>
  <p>I_111345_<strong>333345</strong>_File4_chupapimonienio</p>
  <p>P_1156_<strong>3556</strong>_File5 idk what</p>
  <p>etc...</p>
  <p>I want to create column where i will see only bolded values, how i can do that ?</p>