You need to use the Measure Profile feature. (see pic.1)
1) select the "Measure Profile" command.
2) Click the first point and then click again a second point along the line you need to cut.
3) Right click to finish the command.
In the window that opens you see the profile of the cut you assigned. From there there is a save command that lets you save the profile in different formats such as .shp, .dxf, .jpg, .png etc. (see pic.2)
you can make some adjustments with the sliders to the depth range of the cut, an offset of the cut and the display of the point (solid, color, classification etc)
In order to use this feature you need to have the project referenced. This can be done with georeferencing, or with Control Points, or with scale bars.