Sorry misread your post.
This from the msdn website
"One of the limiting aspects of using the AutoFilter feature in a
business solution is that it has no directly associated event in the
Excel object model. In other words, when a filter is applied or
changed, by a user or programmatically, there is no explicit event for
the activity."
The article goes on to explain a way to capture the autofilter event
with the use of smart tags. Will let you get your head around it. It
is worth reading.
http://msdn.microsoft.com/en-us/libr...ffice.10).aspx
Take care
Marcus