how to add a "person" in a "person field"?

[reiniertc]

How do I correctly add a "person" in a "person" field of a sharepoint list?
I've tried using the user-id, the full name and the emailadress of the user .

When I enter the person in the list via Sharepoint and than retrieve that list, I see something like:"{number};#{full user name}
the number is always the same per user.

[JLauwyck]

I've been able to add 'person' fields as well as 'lookup' fields via the lookup (or magicLookup) function.
If you know the number (I suppose sort of ID?) and name of a person, you can get the correct value to save via $sp->lookup'{number}', '{full user name}').
Full working example:
$sp->write('{List Name}', array('Title'=>'Example item','PersonLookup field'=>$sp->lookup('{number}', '{full user name}'), 'OtherColumnLookupField'=>$sp->magicLookup('{Value}', '{List in which you lookup}'));