What you want is also known as Cascading Prompts. Crystal Reports XI supports Cascading Prompts. For previous versions of Business Objects ver 6.x or ver 5.x, please take a look at this Designer FAQ entry for a work around.
State is an object based on a LOV contained somewhere that is empty.
When clicking Show List of Values, a Hook will see that “State” button had a “Show List of values” clicked. The hook will determine that a certain “Country” was selected and dynamically populate the LOV with the Full State Excel Spreadsheet.
Infoview would continue working properly, getting the States from the dynamically populated LOV.