Not sure if this works for opening a document, but you want to add a LinkToItem="TRUE" on other column.
<ViewFields>
<FieldRef Name="SomeField1" LinkToItem="TRUE" />
<FieldRef Name="SomeField2"/>
<FieldRef Name="SomeField3"/>
</ViewFields>
This link explains how to do it for a list: http://thechriskent.com/tag/listmenuitem/
you can also add the ECB menu to the column:
<ViewFields>
<FieldRef Name="SomeField1" ListMenuItem="TRUE" />
<FieldRef Name="SomeField2"/>
<FieldRef Name="SomeField3"/>
</ViewFields>
Another SharePoint StackExchange Question/Answer on this: Change Title (linked to item with edit menu) to different columnChange Title (linked to item with edit menu) to different column
another reference: http://kamilmka.wordpress.com/2011/04/20/enable-context-menu-in-a-custom-column/
