move parallel 3D

Hi,

I would like to make a parallel copy of a line which was digitized in 3D. I want to keep heights and move the line only in XY plane (top view).

When I use function Move Parallel I am not able to make a copy, or the copy of a line is moved  in the Z direction with wrong XY distance .

Is there any way to block the z-axis and make a parallel copy in the top view?

Thanks for Help

- Katarzyna