CCK module + custom emoticon field

I am assuming your using views and you mentioned cck, so this is how I would go about it(may not be the best).
I would first create a Content Type: Emoticon, have three simple fields: Title, ImageField, and Plain-Text. This would allow you to add as many emoticons as you want.

Then create view that displays all emoticons, i would name it something like EmoteCity. I would include in it the Title, ImageField, and Plain-Text fields. Be sure to add filter for type and published also. Then go in and build a template file, should be named something like views-EmoteCity.tpl.php or similar forgive me for the name convention violations.

The next step would be to make a javascript function that when clicked would paste the image into the current cursor position. Once your script is complete, jot down the page location for this. Then build a template file for the blog post page(devel module helps with this a lot) and add a iFrame set to the location of that node. I think there is also a way to reference just the node inside of another node(panes maybe could be the way I am thinking).

This would basically accomplished what you have described. I just did a basic overview, but let me know if you need additional help.