Make "Company" Field editable

Hello Experts,

We are using E-Sourcing 5.1 with most of the out-of-the-box functionality. When creating an Auction, header section contains field "Company". This field appears as read only, and populates automatically based on the company defined in the user profile.

I tried making this field editable by means of page customizing (UI ID: doc.auction.multi.universal.auctionevent.ui.buyside.default), but even when I declare field COMPANY as Editable = YES, the change is not reflected in the UI.

Any ideas on how to make this field editable so end-users can select another company code besides the one specified in their profile? Your help is appreciated. Thanks!