I was able to convert the same using replace text
Search Value: (.*)=(.*)&(.*)=(.*)&(.*)=(.*)&(.*)=(.*)
Replace Value: {'$1':'$2','$3':'$4','$5':'$6','$7':'$8'}
Since the number of parameters for me was fixed to 4, this was enough to suffice me! If somebody has got an Idea how to do this dynamically, I am ears!