Great to see folks here using "GTC" good till cancel orders. I myself am with TDAM and can lock up for an extended period of time - 90 days but u also have a window that you can set any date forward. I'm locked up thru Jan 16th 2016 then can reset . Other than this the only way to lock up shares is to request a Cert which i believe might cost you depending on broker

Long and Strong in vault - RMH