Using the External User Exit Templates
All the external user exit templates are located in the \cm_​templates directory. Once the UI Program to be extended is known, the appropriate user exit template can be selected from the templates directory.
Use any editor that supports the JSP file editing and open the approprite user exit.
Determine the base user exit around which to insert your external user exit.
Uncomment the necessary functions, and add your code.
Save the external user exit file as ext_​<JSPfilename>.jsp under the \cm directory. Where JSPfilename is the JSP file you want to extend.
Test.