In Excel 2007, you can still select multiple drawing objects by drawing a selection box. Here's how:

1. Click on the "Home" tab in the ribbon.
2. Click on the "Select" dropdown menu in the "Editing" group.
3. Select "Select Objects" from the dropdown menu.
4. Click and drag your mouse to draw a box around the objects you want to select.

As for changing the length of a drawing line while maintaining its direction, you can use the "Shift" key instead of the "Ctrl" key. Here's how:

1. Click on the drawing line to select it.
2. Click and hold on one end of the line.
3. Hold down the "Shift" key.
4. Drag the end of the line to the desired length.

This should maintain the original direction of the line while changing its length.