Is there a way to change the search parameter on related fields/change the linked label?

Hi all.

I have created a custom module with a related field linked to Opportunities. I am looking for a way to instead of the search box searching on name, it searches for the opportunity code.

It is the simple search and select dropdown, but wondered if there is anyway to change this?

Also as standard the filled in box has the "Name" field as the  display on the hyperlink, however is there anyway to update it to be "Project Code" + "Name".

Thanks!

Daniel