To enhance an Infotype… follow these steps….
Go to Trans. Code PM01.
Select 3rd tab (4th Tab for ECC 6 Version)
Enter ur infotype no. & click on edit..
The screen moves to structure where u can enter additional field in CI_Pxxxx
Save it and Activate.
Come back to initial screen PM01 and click on “ALL” button ( “Generate Objects” for ECC 6)
There u can find the additional fields added to ur infotype in PA30 screen.