[Brian]

Welcome to the forums, spinnej - just click in the white space to the left of a row to leave edit mode and select it. (Drag-select works in the gutter, too.)

Once you have the rows selected, you can copy as per usual. Click in the same spot in the other document to select the row you want to paste the items underneath. (You may need to adjust their indent level after you paste - "underneath" just refers to the vertical position in the document.)

Hope this helps!