Add summary at the group footer based in a second field, Crystal Reports, vb.net
<p>Hello and I hope my question is clear.
I have a report that gets the data this way:</p>

<p>Office 1<br>
 Document 1   some data .... Document Type A <br>
 Document 2   some data .... Document Type Z <br>
 Document 3   some data .... Document Type A <br>
 Document 4   some data .... Document Type B <br>
 Document 5   some data .... Document Type D <br>
 Document 6   some data .... Document Type Z <br>
 <br>
Office 2<br>
 Document 7   some data .... Document Type A<br>
 Document 8   some data .... Document Type A<br>
 Document 9   some data .... Document Type B<br>
 Document10   some data .... Document Type B<br>
 Document11   some data .... Document Type C<br>
 Document12   some data .... Document Type D<br>
<br>
<b>Where Office is the Group, now I need add a summary in the footer of each group, showing the total count per Document Type<br></b></p>

<p>Office 1<br>
 Document 1   some data .... Document Type A<br>
 Document 2   some data .... Document Type Z<br>
 Document 3   some data .... Document Type A<br>
 Document 4   some data .... Document Type B<br>
 Document 5   some data .... Document Type D<br>
 Document 6   some data .... Document Type Z<br>
      -----------------------------------------<br></p>

<p>Document Type A: 2<br>
      Document Type B: 1<br>
      Document Type D: 1<br>
      Document Type Z: 2<br>
 ----------------------------------------------<br>
  <br>
Office 2<br>
 Document 7   some data .... Document Type A<br>
 Document 8   some data .... Document Type A<br>
 Document 9   some data .... Document Type B<br>
 Document10   some data .... Document Type B<br>
 Document11   some data .... Document Type C<br>
 Document12   some data .... Document Type D<br>
      ----------------------------------------- <br>
      Document Type A: 2<br>
      Document Type B: 2<br>
      Document Type C: 1<br>
      Document Type D: 1<br>
 ----------------------------------------------<br></p>

<p>Thanks for your help.</p>