List Groups/Parameters name in a shared parameter file?

[x_cad]

Hi,
I understand how to search/apply a group/parameter name to a shared parameter file but unable to get a list of the groups and parameters names. I had tried both the DefinitionGroup and DefinitionGroups classes. I was able to get a current name of the group from DefinitionGroup.Name but do not know how to access the next group name. I am using VSTA instead of SDK for revit 2009 and is VB based.
Many thanks to any suggestion!

[x_cad]

Ok!
The trick is to use GetEnumerator method under Autodesk.Revit.Parameters.DefinitionGroups to get each group name in the selection.