Are you sure the name was Rosine? Most bluegrass songs mentioning Rosine pay homage to Rosine, Kentucky, the city of Bill Monroe's birth. I've found quite a few instrumental songs about Rosine and a few vocal songs with Rosine in their name. This one is the most promising, but I don't think it's what you're asking for: https://www.youtube.com/watch?v=XCzF4qnVcxQ

If you know the station you can always try calling them and asking if they're familiar with the song. Especially if it was fairly recent. One time I waited too long to ask and when I called the guy basically laughed at me and hung up--still haven't found the song to this day! Basically, my way of saying, don't dilly dally!

If you remember any other details about the song that could also help find it.

There were a few songs I couldn't find online but the only one that may be of any use is "Rosine Quisine" by Paul Adkins on his album Modern Times. It was only 5 bucks so I ordered the CD and should be able to tell you for sure soon.