I'm not sure if I got it right... So, the Lithuanian Polonia (Polish minority there) speaks some sort of Polish/Belarusian? I must say I've never heard of that "creole". It is true that people coming from those eastern regions (especially those, who moved west after the World War II) are thought to have some strong accent and use a few regionalisms... Same for Ukraine - see the old good Szczepko i Tonko
http://es.youtube.com/watch?v=osXqBbDbQeE&feature=relatedMaybe during all those years after World War II there has been developed some sort of "mixed" language. Sounds pretty interesting; however, we'll need someone who was in close contact with it.
As for the song you've found on YouTube, it has apparently nothing to do with it. I can send a translation of it to your PM, just be prepared: except for some funny stuff, it also has some foul language in it.