It's not going to be possible without customising the screen. The javascript is very simple
var mSelect = VSMCustomJS.GetFieldByDBName('FIELD_NAME');
if (mSelect)
{
var vals = mSelect.GetValue();
for (var i = 0; i < vals.length; i++)
{
var ref = vals[i].text;
var display = vals[i].value;
//Do something here
}
}
You could put this in a function and call it on keydown or on a button press.