Mathew,
Sergey has an excellent solution to work with the data that you currently have. Is it possible though to split that field out into another table linked by your basic 1 to many relationship? It would make sense, if you need to be querying on that data, to have it set up that way for normalization's sake & just easy access.
Just an idea. I know sometimes we're bound by our situations.
Paul A. Busbey
Victoria Insurance