Variable Offset (Z Axis)

Greetings,

At the moment I am trying to achieve an offset of a curve that varies on differrent parts.Offset sould be one tenth of a part´s length.  Also for me is important that the offset is in Z direction. I have used shatter option and based a separation of curve on a position of a point. After that i have blended them again. For me is very important that the point remains on that specific point because it represent ground level. That way I can deform a curve if necessary and point will remain exactly on that place.

This curve is used for a creation of truss. I have two version of Trusses. Is it possible to make offest like this and than to connect it to any of those trusses.

Thank you in advance