[amibroker] Newbie questins

["tipequity" <l3456@xxxxxxxxxx>]

1. how can refer to a calendar year ago prices (end of the day), I 
tried the following and it did not work:

CloseAYearAgo = Ref(C,Year()-1);

2. how can I get the first date for which we have data (end of the day)

thanks

Cam