Response to Image URL using Code Behind

Hi guys, sorry just not really sure on how the title should go.
Anyway, I got this scenario:
If URL point to a URL, let say http://samplewebsite.com/sampleimage.gif,
I may want ASP.Net to handle the "sampleimage.gif", so that it can be fetched from database server, using HttpResponse.Write();


My question is how can IIS/ASP.Net recognize sampleimage.gif is actually pointing to a aspx page?
Is this possible?


Anyway help is appreciated. Thanks
...