DeformByProjecting is one of those scripts for 3ds Max you need to have on hand, especially when working with complicated elements such as land, where you need to insert walls or roads.
The grace of this tool is that basically allows you to project a geometry over another, keeping the original volume of the object to be adapted.
Click here to download the demo.
The full version can be downloaded from this link for a value of US $ 12.
You can review the complete documentation DeformByProjecting here .