So, if I understand you correctly, you want to do different things based on the type of an object, but you don't want to implement those things inside the object itself?
Sounds like a job for the Visitor
pattern...
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus