MySQL Regular expression

I'm not a 100% sure if this is the correct list for the following question, so I shall apologise beforehand if I upset any one. Now, I have a field in my database table in the following format: 100,30,443, etc. Representing prices for 52(53) weeks of the year and comma delimited. Now I need to check the price for a given week within my query. The problem however is that the week number is variable. Is there a way to count the number of non-consecutive occurances of a character, in this case commas, in a regular expression? I know ,{#} will check for # occurances of consecutive occurances of #, but is there a similar way to check for non-consecutive? Thank you in advance. -- Regards, Owen Franssen Twisted Design