How do I change the delimiter for a group checkbox field?

One of my fields is a group checkbox. When storing the values of the items checked, it looks like the values in MySQL are being stored with a carriage return as the delimiter. How do I change the delimiter to a comma? The reason why I want to change the delimiter is because I want to query that field using FIND_IN_SET('value2','value1,value2,value3'). I am open to other suggestions too.