Joydeep,
I think you may have to explore the Implicit Enhancement Points in program SAPLCOIH where the ABAPer should be able to set the screen to display mode. ABAPer can start by searching the program by field names which are in the PR screen to arrive at right include/form. So in case your task is not done through BAdi then you (ABAPer) may spend some time on this.
I spent some time in the similar way sometime ago and could achieve IW32 to Display mode through Implicit enhancement Point in program SAPLCOIH, which I recorded here. IW32 to Display mode
May be this work might readily suit to you or this Display effect is applicable to only Order fields. Your ABAPer can research using clues from this post.
Good luck
KJogeswaraRao