Do not disassemble CSV manually if you have convenient quality libraries available . You are welcome!
CSV parsing has many potential pitfalls, and this library, according to my testing, solves most of them neatly.
However, if this is one task, and the lines are always similar to your example, you can use a regular expression, for example (VB.NET syntax may be incorrect, please correct):
Dim s as string = "1, 2, '1,233,333', '8,444,555'";
Dim r as Regex = new Regex(",\s");
Dim re() as string = r.Split(s);
, . , :