Doubts in String Manipulation

Hi,
I am having the doubt in string manipulation. I am having the following string value
string input="(Grade=A && Standard='12')||(City='ABC' || Region='India')&& (Name=='John')";
I would like to do the precedence condtion so that i want to split the above string in the followung form to identify the precedence group. 
Grade=A && Standard='12'     --arr(0)
||                                            --arr(1)
City='ABC' || Region='India' --arr(2)
&&                &nbs ...