Report Designer - Parameter 'user prompt' condition query dependent on signed in user

Hi community,

I want to create a report parameter which prompts the user to select attestation runs.

In this select-contol only AttestationRuns should be displayed, where the current user is owner (AttestationPolicy.UID_PersonOwner)

To filter the options for this parameter the property (Condition (query)) is used.

My problem is, I don´t know how to get the current user reference in this query.

Until now I tried to reference the user with a second parameter UserID as $PC(UserID)$ but this is not working (I don´t know why). The UserID-Parameter is initialized with 

If Provider.Contains("UID_Person") Then
Value = $UID_Person$
Else
Value = me.Connection.User.Uid
End If

but this seems only to evaluate on report run and not at the time of subscribing the report, so that limiting the options would be possible.