Add Fields from table ADRC (Fields Name 1 to 4) for Open Item Processing

Question

Hi SAP Expert:
Our client requires vendor/customer name to be displayed in the open item processing line layout for transaction code f-58, so they can double check if the vendor name is complete as intended. 
We intend to add fields from table ADRC instead of REGUH since the characters in maintaining vendor/customer name is 40 characters and REGUH - ZNME1s are only 35 characters. 
We have managed to add fields from ADRC and change the SAPDF05X program and were able to display the names in open item layout, except that the program seems to "automatically" create a generic table which only carries 30 characters of the vendor/customer name.  The source table should be RFOPS_DK but the program automatically looks up from table RFOPS_GEN for the particular fields - Name 1 to 4.  Is there a way to "instruct" the program to use RFOPS_DK instead of RFOPS_GEN?
Hope this will merit somebody's attention... Thanks !!!

Answer 1

Thanks,  i have assigned the layout via o7v3,  it is the program that i have a problem with,  actually another program that we change is the program MF05BFPO where it generates data to be displayed in the FBZ4 screen,  though we add a field with 40 characters (ADRC Name 1 to 4)  what the program dispalys is a 30 character Name1 to 4 from structure RFOPS_GEN. 
My question is can i extend/change the structure RFOP_GEN to 40 characters,  is there any SAP standard program that will aftected if i do so?  thank very much...
Lorena