Making one field editable in the attachments detail

Hi there,

In the Attachments detail (screenshot attached), I need to make the Category lookup field editable so users can select values from a lookup (selecting the category of the attached document). The rest of the fields (e.g., Name, Created On, File Size) should remain read-only.

It seems that the default setting for all fields in the attachment detail is read-only. Is it possible to override this for the Category field while keeping the rest of the fields read-only? There seems to be no option in page designer to make the detail/specific fields read-only - could this be done using code?

Thanks in advance!