InfoPath Dev

I have a form with fields that I would like to validate based on a SharePoint User Group.  I'd like to use the SP groups instead of roles since the SP groups are already existing and working for other SP libraries.  Also, this would cut down on modifying the form template in cases where users change SP groups.  Is there a way to validate fields by SP groups instead of the infopath user roles?

 Use Infopath 2010's  Person/Group Picker (Contact Selector in 2007) control for this.

Instead of the Contact Selector, I was able to use MS Outlook distribution groups to as the user roles as a workaround.

Okay, I thought the MS Outlook distribution groups would work but it doesn't.  It seems like if I set User Role 1 to group name CORP\DG Test Users, the all the names in this group would automatically be a part of that user role so I'm not really sure how the Groups options works.  I tried useing the Contact Selector but everytime I try to add Context.xml, it tells me the "The form contains an invalid XML file"  and says there is an invalid character in <site Url=.  Any ideas on how to correct the expression?

The contact selector was not an optimal solution for my form.  The solution described in a separate forum however works well.  http://www.infopathdev.com/forums/p/23678/82493.aspx#82493

Thanks!