Fetch one more column in the grouptable..

Hi again,

Just a quickee; I have the following code which fetches a single group and
works well.

$options['filters'] = array('group_id' => $group_id);                
$this->admin->perm->getGroups($options);

Now the thing is that I have one more column in the grouptable that I would
like the getGroups-function to include in the result. But no matter how I
try I cannot seem to get it work. 

I have tried (among other things):

$options['fields'] = array('name_of_my_column' => true);

And with different combination of "table","alias" and other subarrays but I
obviously doing something wrong =/

Thanks!
//jan