Hello Parveen,
Good News, Finally I am able to show a fm-free solution to your query.
The Table you need is KSSK_INOB (view).
See the picture below (SE11)
I passed the Equipment number to the field INOB_OBJEK field of this Table. (You should fill OBTAB field also with value 'EQUI' to avoid getting matching lines related to other Tables if any). See what we got.
I got the OBJEK number which we needed to pass to AUSP table. I think the Mission has been accomplished .
So the join is
EQUI-EQUNR <--------------> KSSK_INOB-INOB_OBJEK
KSSK_INOB-OBJEK <-----------------> AUSP-OBJEK
Regards
KJogeswaraRao