CYYMMDD format in DB2

I have a date format in db2 which has a date in
the below format. CYYMMDD in which the C stands
for century, YY for year, MM for month and DD
for day. Right now am storing it as string. for
example, 1082702. How to convert this string to
date? I want to find the diference between the
dates which are in the above format. Please
help.