You'll need to cast myCadEntity into an AcadBlockReference. Then you can check the myBref.HasAttributes property, and call the myBref.GetAttributes Function, which returns a Variant(Object) array of AcadAttributeReference's, which you can loop through.
You could also save some trouble by making a selection set which is filtered to only have block references with attributes.
Then you could do:
dim atts() as object
For Each Bref as AcadBlockReference in mySelectionSet
atts = Bref.GetAttributes
For Each AtRef as AcadAttributeReference in atts
'Do whatever you need to do
Next AtRef
Next Bref
Sorry, I use VB, but you should get the idea.
Dave O.