Here is a small HTA applet that I have built to export the membership of various groups in Windows Active Directory. It provides some basic filtering (owner, specific OU, name contains), plus 3 modes of export, XLS, CSV, or HTML to screen. Beware, if you have office 2007, XLS is XLSX format.
To run this in your environment, it will need to be modified:
line 27 & 28 strHTML=strhtml&"All OUs"
strHTML=strhtml&"This SUB OU Only"
