Customer Master Change Pointer

Hello Experts,

My requirement:

When ever customer master is getting update or creating,system should trigger a program which can find entire masterdata details.

So.please explian with details procedure for trigger a program through Customer Master change pointer.

1) How to activate change pointer Message type (DEBMAS) and Table name and key field.

2) How to call a program.if any BADI please suggest me its highly helpful.