Write SQL query to solve given problem: Who is the oldest player who played for Avangard Omsk during the regular season in 2000-2001?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.PlayerName FROM SeasonStatus AS T1 INNER JOIN PlayerInfo AS T2 ON T1.ELITEID = T2.ELITEID WHERE T1.SEASON = '2000-2001' AND T1.GAMETYPE = 'Regular Season' AND T1.TEAM = 'Avangard Omsk' ORDER BY T2.birthdate ASC LIMIT 1