FFD (PATH) .... anyone ever heard of anything that can do this?

Hi, was wondering if anyone knows if this script exists. Basically what I wanna do is deform a spline in the Z axis, non proportionally, for example steep at the beginning then smoothing at the end, using controls similar to an FFD modifier. It´d be almost like a curve in nurbs with control points, except I don´t wanna use nurbs cos this is for architectural purposes and has to be splines for extruding etc... So imagine a line with staight parts and some curved parts, using all vertex types, corners,bezier and bezier corner. Now let´s say I wanna stretch it in the Z direction, let´s say proportionally to make it easier to understand, it would be using 2 control points, one at the beginning and one at the end and by pulling one up or down it would shift the rest of the spline accordingly along the length of the spline. I know I can use a path deform but that is too impractical when u have hundreds of lines to draw. I need a simple tool that could, like an FFD modifier, allow quick changes without having relational objects and complicated dependancies.
thanks guys,

FFD path.jpg105.29 KB