Make Few segmens as Read only in expense item accounting flexfield

Summary

Customer wants to enable few segments as Read only in Expense item accounting flexfield while entering the Expense report.

Content

Hi Experts,

We have enabled "EXM_ALLOW_FULL_ACCT_OVERRIDE" profile option at Site level as Yes, So in this case, user can see the whole account code combination and they override the existing account, But  customer wants to allow only two segments out of 6 Segments to edit by the user and those segments are not Cost centre and Natural Account. So how do we disable or read only the remaining segments in the complete code combination at expense item level.