You have two options:

1. You want to enter the customer fields along with the SAP fields on the data entry screen. Proceed as follows:

• Define customer Include CI_CATSDB in the ABAP/4 Dictionary. Include only fields in the customer name range in structure CI_CATSDB. Otherwise, this may cause problems during a system upgrade. Use only fields of type 'CHAR' and 'NUMC'.
• Activate the customer fields using a special Customizing transaction for the Time Sheet.

1. You want to enter your customer fields on a separate dialog box. The advantage of this option is that you can output context-sensitive information here - information that is needed to enter correct values in your additional fields. In this case, proceed as follows:

• Define customer Include CI_CATSDB in the ABAP/4 Dictionary. Include only fields in the customer name range in structure CI_CATSDB. Otherwise, this may cause problems during a system upgrade. Use only fields of type 'CHAR' and 'NUMC'.
• Define subscreen SAPLXCAT 1000. This subscreen is then included in the dialog box that is called. This subscreen contains your customer- specific fields.
• Define a menu option to trigger the dialog box with your customer fields.
• Define a function module to receive data in the transfer structure FIELDS from the calling program.

Function/Program:
• SAPLCATS+CU1: Additional fields
• EXIT_SAPLCATS_005: CATS: Export Data to Customer Dialog Box
• EXIT_SAPLCATS_008: CATS: Import Data from Customer Dialog Box
• SAPLCATS8900_CUSTSCR1_SAPLXCAT1000: CATS: Customer Function