Hello Kiran,
In my view for IK17, it should be structure RIHIMRG. The solution you are following is an ABAPer's job, which has 2 steps.
1. Appending RIHIMRG structure (in the include table CI_IMRG) with Equipment Descriptionfield(Data element KTX01). (through Tcode SE11)
2. Writing suitable code in user-exit IWOC0004 to display this field (for IK17 Program RIIMR020).
Your ABAPer can make use of detailed Example documentation provided in this User Exit for FM EXIT_SAPLIREP1_001.
The other reply in that referred thread, suggests a simple functional way of addressing the requirement through Infoset Query or SQVI.
KJogeswaraRao