Activating a group basically enters the edit mode associated with the type of group. E.g. a vector group will enable the edit toolbar for that gorup and an AGG will bring up the image colour tool. Be sure to pass a combined name containing both the view name and the group separated by a "/" or "\".

public void ActivateGroup(
	string str1
)

Public Sub ActivateGroup ( 
	str1 As String
)

public:
void ActivateGroup(
	String^ str1
)

member ActivateGroup : 
        str1 : string -> unit