Well I got this contour site drawing from someone else and had a reference image which had the elevations written, but no tags were present in the drawing.
I am done with it now though, I raised the contour lines manually in AutoCAD and then imported the 3D into SketchUP.
Though I would still like to know the lisp for doing it via text tags in AutoCAD.
Here the contours were brought in from rhino. I otherwise usually use global mapper to get conotur maps.

Sorry yes, i meant the z axis - silly me. They are polylines and extracted from AutoCAD. So basically, what I need is that by single click the lines move up/down as prefixed by a constant number which is input initially(something like how push/pull command works for surfaces), instead of having to select one contour line and putting in its elevation one by one. The site I am dealing with has contour interval of 1 m and as it is a detailed design of a large area, I can not make the intervals larger.

Hi,
I wanted to know if there was any tool or plugin to move contour lines, in the y direction automatically without having to select each one and move them individually ?