It's working, modified the PLY file as mentioned and able to achieve the result. I am adding script here which I used to implement the same:
import plyfile
from plyfile import PlyProperty, PlyListProperty
################################# PLY file Manupulation #############################################
#Convert File format using
https://github.com/dranjan/python-plyfile
#Modify Header to read Scalar Density parameter
#Update Ply Header: Modify ----->> "property float scalar_value" from "property float value"
print("Please Wait!!! Transforming File ----->")
file = plyfile.PlyData.read("FILEPATH\\Poisson.ply")
file.text = True
file.elements[0].properties = ()
file.elements[0].data.dtype.names = ['x', 'y', 'z', 'scalar_value']
file.elements[0].properties = (PlyProperty('x', 'float'),PlyProperty('y', 'float'),PlyProperty('z', 'float'),PlyProperty('scalar_value', 'float'))
file.write("FILEPATH\\Poisson_C.ply")
print("File Modified !!!!!")
#####################################################################################################