How to change the RSS icon into a pre-assigned image.

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Hi Guy, any one know how can I use a assigned image instead of the orange RSS icon when I link my blog to facebook?
here's my case: I have a "like"button on my blog, and when people like it, it will show on the facebook news feed. But instead of the orange RSS icon, I would like to show an image instead.
Is there a way to do that? or am I just asking too much?
Thanks everyone in advance.