I'm not quite sure what you're asking, but...
If you're trying to sort entire rows by the value in a single column, you need to select the rows. When you go to the sort menu, simply select the column you want as your sort key. You might have to go to the Options tab to indicate whether or not your data selection includes a header row; like in Excel, how this comes up seems to be completely random (in other words, I've never discerned a pattern to how it works).
If I'm misunderstanding your question, please try again!
Dave