PS: jak usunąć elementy z listy oddzielanej średnikami

#connection objects
$sqlconnection=New-Object system.data.sqlclient.sqlconnection
$sqlcmd= New-Object System.Data.SqlClient.SqlCommand
$SqlAdapter = New-Object System.Data.SqlClient.SqlDataAdapter
$DataSet = New-Object System.Data.DataSet

#connect MYDATABASE on MYSQLSERVER
$sqlconnection.ConnectionString="Server=MYSQLSERVER;database=MYDATABASE;Integrated Security=True"
$sqlcmd.CommandText="select * from TABLENAME"
$sqlcmd.Connection=$sqlconnection
$SqlAdapter.SelectCommand = $SqlCmd
#that is strange way of getting results - they are popullated into $dataset array. 
$SqlAdapter.Fill($DataSet)|out-null


#now when we have everything in an array so we can manipulate on data
#first define hashtable for computers with admin accounts
$unsecure=@{};
foreach ($row in $DataSet.Tables[0]) {
    #how to remove correct group/user names from check? one can try to 
    #operate on strings but it's so... bueee
    #it's easier and nicer to have an object for comparison. hashtable is perfect
    $splitrow=@{};

    #column 1 in my database contains memberof information separated with semicolon
    #f.ex. 'domain admins;administrator;non-admin-user;'
    #so change this string into a hashtable:
    $row[1].split(";")|%{$splitrow.add($_,0)}
    #the second parameter is obligatory to fill but tottaly unimportant in this situation. 
    #so i put '0' but could be anything.
    #now it's easy to remove correct entries which are not interesting for this task
    $splitrow.Remove("administrator");
    $splitrow.Remove("Domain Admins");
    $splitrow.Remove("grupa_operatorow");
    $splitrow.Remove("specjalna_grupa");
    #as there is ';' on the end it will always produce one additional, empty record. 
    $splitrow.Remove("");

    #if there are any unwanted logins, the number will be greater then 0
    if ($splitrow.count -gt 0) {
        #add entry to final table. i want to have it back as a string so -join is going to be helpful
        $unsecure.add($row[0],$splitrow.keys -join ";")
    } else {
        #out of interest - just informational
        echo "KOMPUTER: $($row[0]) jest ok";
    }

}

#now print information to a file
$unsecure.count|out-file c:tempadmins.txt
$unsecure.getEnumerator()|Sort-Object name|out-file c:tempadmins.txt -append