Andy, there is a perfectly good way to do this. I have been using this method since TTD.
First create a new folder with the name of the graphix you want in the library, then copy the entire folder to the Integration Designer/Bitmap Libraries directory, then your folder name should show up in the list like this:
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After that, you can find all the buttons in that window like this:
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I hope that helps Andy, let me know if I should explain more.
Joey