base 2.xml is the template all skins inherit, its probably a better idea to edit main.xml in the actual template (add a new <TEXT> section near the end, for example).
50,0,100,100 is the position, and Alignment specifies how the text is aligned in the element.
The position is a rectangle: left,top,right,bottom - in this case it means start at 50% from left and 0% from top, to 100% of right and bottom (ie. from the middle to the right end)
If you simply change this to say 0,0,50,100 and set Alignment to "2" (like you already did), it'll be in the bottom left corner instead (from 0,0 left/top to 50/100 right/bottom, from the left edge to the middle)
This position works out since RootText is a strip at the bottom of the screen and not the entire screen, and you position relative to that.
That gives us this snippet, which you can either add to the base 2.xml, or copy the TEXT section from the base to the main.xml and then add it there.
<Item Text="Current Zone = [Zone]" Location="*" TextColor="FFFFFF" Rect="RootText\0,0,50,100" Capitalization="0" Alignment="0" Alpha="50" Size="[Medium Text Height]" />
Note that I recommend copying the template, renaming it and copying the TEXT section to the main.xml, since otherwise an update to MC will overwrite your changes.