Add( [in] BSTR strType, [in] BSTR strParentUniqueID, [out,retval] VARIANT *rt)
This function is called when an 'Add' function is executed
Inputs:
strType - The identifier of the
node being added
strParentUniqueID - The Unique id of the parent to the node being
added
Return value
A variant safearray (with LBound 0 and Ubound 2) containing
UniqueId, Type, Message in the stated order. The message will be
shown to the user. UniqueId and Type should identify the new
node.