How do I calculate age using a 12 digit social security number in MS Excel?

[hazuha]

How do I calculate age for current year 2011 using a 12 digit social security number (Malaysian) where the the first six digits is DOB (yy/MM/dd). I tried Select =Left 6 digits and calling that DOB but this DOB field is not date format. If I Select =Left 2 digits, do add with 1900 and -2011 (current year) will have trouble with y2k and above birthdate, e.g. the child with birthdate 090606 (yy/mm/dd) will miscalculate for the year of 1990 instead of 2009. Can anyone help. I am using Excel 2003 compatible with 2007. Thank you very much.