how to extract a particular column only when it is updated

Hello,

I need to know if there is a way to extract only a particular column of a sqlmp table in HP Nonstop guardian.

My source table is CSTEST and target table is BSTEST

CSTEST Table structure as below

CARDNUM                        VARCHAR(19) NO DEFAULT NOT NULL      

PVD                            CHAR(10) DEFAULT NULL                

NAME                           CHAR(15) DEFAULT NULL                

ADDR                           CHAR(30) DEFAULT NULL                

                                                                   

Target table BSTEST structure as below

CARDNUM                        VARCHAR(19) NO DEFAULT NOT NULL

PVD                            CHAR(10) DEFAULT NULL          

NAME                           CHAR(15) DEFAULT NULL          

                                                              

Column CARDNUM is Primary key.

I only need to capture PVD column only when it is updated on source. Also please note that my extractor is datapmp and reads audit trail of Hp nonstop system.