Wanted something like "Group multiple values" in the "Configure Relationship" settings from views

I don't think it's a duplicate of #556232: multiple values in views because in this issue there is one field with multiple values.
But in my case i got the multiple values of different nodes whereat each field contains only a single value.
Nevertheless i changed my code like described in #556232: multiple values in views.
As i expected it didn't change the output.
It change the output, if you have a field with multiple values and use the "Group multiple values" option.
But my problem is that there is no option like this for multiple values consisting of a singular field from different nodes.
Thanks for your help. Maybe you have another idea.

Markus: Thank you very much for your idea.

So for other people with this problem here is my way:
1) Install and enable http://drupal.org/project/views_customfield
2) I find it helpful to read #467190: Basic usage information
3) In the view add the field with the node references and select the options "Exclude from display" and "Group multiple values"
4)Add a Customfield "PHP Code".
5)In the "value" field of the Customfield "PHP Code" you can paste the following code and customize it to your needs. It's only an example with field and table names which will not exist on your system. So it will not work without changing them.

/* Uncomment the following line to see the accessible fields
 * print var_export( $data, TRUE );
 */
foreach( $data->node_data_foo_nid as $value ){
   $nid_wherein.=$value['nid'].", ";
}
$nid_wherein = rtrim( $nid_wherein,  ", " );
$dbq_var ="select field_foo_value from content_type_foo where nid in (" . $nid_wherein . ");";
$result = db_query( $dbq_var );
while( $row = db_fetch_object( $result ) ){
   $field_values .= $row->field_foo_value . ', ';
};
$field_values = rtrim( $field_values,  ", " );
echo $field_values;

That's it. Hope it works for all who test it.