Is there a way to shrink-wrap only a selection of mesh to another without effecting the whole mesh?
When I shrink wrap a mesh to another mesh, sometimes I lose a lot of data on the other side of my object.
The solution is a vertex group. You can assign a value from 0.0 to 1.0 to any vertex in the group and the Shrinkwrap Modifier will only partially or fully affect verts within the group with a value > 0.0
That way most of your mesh can remain unchanged. Many modifiers have that option.
The green plane has a vertex group including all verts, but the outer two rows have a weight of 0.0 (blue) and the Shrinkwrap is guided by this vertex group. Excluding them from the group would have the same effect.
The option to have some verts react partially to the shrinkwrap offers nice solutions to gradually adhere to a surface. Look how the bevel of the small cylinder behaves: