how to create hook to retrieve a column and display on record view

I am trying to create a hook that will retrieve the relevant column I want to display when selecting a relate field. By default this brings a back and stored the id in the custom table. I want to bring back a column related to this custom table

in my module vardefs added 

'name' => 'newcol',
'type' => 'varchar',
'source' => 'non-db',
'len' => '255',
'vname' => 'LBL_NEWCOL',

I followed this to create the hook

Problem is I do not see the new field to select and display on record view. And how would I make sure it relates to on change/type/select of my drop down?