You can either create a new screen or copy an existing one.
Enter the program SAPLXLRF or SAPLXLHU in the screen painter.
To find out which program you have to enter, enter the program SAPLLMOB and the dummy screen number 1xxx in the screen painter. The Flow Logic of the dummy screen contains a call for the customer-subscreen in which the respective program (SAPLXLRF or SAPLXLHU) is included.
1. Enter the program SAPLLMOB and a screen number.
2. Choose Element List and delete the last field, the "OK_CODE".
3. Choose Subscreen in the tab page Attributes in Screen type.
4. Save your data entries under the relevant development class in the customer's namespace.