Need a SQL Script for Compare the Row above to that Row

Hi ,

Looking for some Script here for resolving my issue.

Actual scenario is... A.B,C & Posting date should sort ascending  and to find the Expiration date change.

See the first two ROWs of "C" Column having 1470328PC and Posting Date 12.12.2014 and Expiration Date is 31.05.2016.

and go to the next "C" means 3rd row 1463127PC then the Expiration date of the "C" is 30.04.2016.

here when A,B is constant and C is changing then should compare the Expiration date to the previous Expiration date of "C" column.

Example...  the Expiration Date of 1463127PC is less than 1470328PC's Expiration date.

then need to make that row highlight.

can any one give some pseudo logic for the above scenario.

Thanks in advance,

Thanks,

Gundala