Thread Icon - Like the paperclip if there's attachments

[Lurk]

How would I go about adding an image that would allow me to put an icon where the paper clip shows up if a certain option is ticked?

Like, if I set this option to yes, this image will show up, etc.
Another example is: If it is marked as a sticky, it'll be moved to the top and have a pin icon. I want to replicate that, but minus the move to top. Just an icon appearing.

Thanks in advance!

Anyone?

Also, how would I do this with an option on posting the thread, like a checkbox or something?

So, upon posting a thread, i can put a "This thread is a ____ thread." and the image will show up and be marked.