leaving a field editable while using custom code to insert a value, in editviewdefs.php?

editviewdefs.php 

0 => array (

'name'=> 'somefield',

'label' => 'lbl_somefield',

'customCode' => '{$someVariable}',

),

Works great! Yet there is an inherent issue, it prevents the field from being editable by the user. Is there a way to do this and only pre-fill the field?

-Alek