Need help with custom eval code field

[TalkVirginia]

I'm working on an addon for vb3.8.6. I have my development site in debug mode and in the admin cp I'm trying to add an option that will have 2 text fields and a button. The button would execute some ajax code that would return some xml. The xml should then be formatted and displayed as a dropdown with a list of names. The admin should be able to select a name and save it to a custom table.

Is there anyone that could help me with this or point me in the right direction. Maybe an example somewhere to get me started?

Thanks in advance,
Jim