MCMSEG Enhancement for 2LIS_03_BF

Hello Gurus,

I want to enhance MCMSEG with the following fields:

LABST

SPEME

INSME

MATKL

SPART

MTART

BISMT

XAUTO

XBLNR

LBKUM

SALK3

VERPR

to have them available in communication structure in LBWE for the enhancement of 2LIS_03_BF.

I have 2 questions:

1. Where should I put my append structure in MCMSEG (in which include)?

2. I have 2 fields that are already available in MCMSEG: MTART and MATKL but are not visible in LBWE. Also XLABST, XSPEME, XINSME are similar to my requirements but not visible as well in LBWE. How should I handle this situation? Do I still need to make an append structure for these fields to have them with different names (ZZXXXX) and in component type (XXXX)?

Thank you!