Create fields from one filed that is seperated by commas

I am wondering if anyone knows an easy way (or a trick) to extract fileds from a field that has several data elements in a single field seperated by commas. For example; filed1 has the data “2222,3333333,444444,56789”. I want to extract these as Field2 = 2222, then Field3 = 3333333 and so on. The size of each field will change every time I have to extract and so will the number of comma seperated fields. There may be only one filed (no commas) in field1. Any ideas? Did I explain this good enough?