Last character of a dynamic string

Hi ..

I want to get into different field of stirng .For example there is a field zdefinition-definition .I want to get 11  in    zdefinition (ZI_CAM_KALINLIGI_11)  string if there is no third digit at last I want to equalize it as '0'  .And I want to build 3 column 1 cl1 1 cl2  0 cl3 .How can I do this ?    ZI_CAM_KALINLIGI_11 this field variable it changes up to 30 character.