Static and dynamic parameter field

Hi, I want to create a parameter field to select country. This parameter field has 3 values: USA, CANADA, and Others. If user clicks on 'USA' the value will be USA and if clicks on 'CANADA' the value will be CANADA. But it user clicks on 'Others' there will be a prompt for user to input another country. This seems like a mix between dynamic and static, and I don't know if it's possible to do that. Could someone help me?

why not just sort them as Canada and USA as the first two then everything else alpha? Otherwise you would likely need to do a cascading param and need some table data to support it.

Well it looks like you want a cascading prompt which I have only done with dynamic prompts.  But there there would be no relation between USA, Canada and others.  Not sure if this is possible, but I have been surprised before.