MATLAB: How to combine two vectors? HOW TO SPLIT VECTORS ACCORDING TO INDEX

Question

I have a vector say A = [60,600,15]

I extract any value from this vector A using its index

Eg: If i extract A(2) from A. Then i create a vector B of same length as of A

    and place that value in its respective index!
    And the left over values will be in vector C = [60,15]  OF SAME LENGTH AS A

that is B(2) = 600 and C(1) = 60 and C(3) = 15

*THE FINAL OUTPUT SHOULD BE LIKE B = [0,600,0] AND C = [60,0,15];

NOW USING VECTOR B AND C HOW TO COMBINE THEM TO OBTAIN VECTOR D = [60,600,15]*

CASE 2: IF I EXTRACT A(1) AND A(2)

THEN VECTOR B = [60,600,0] AND THE LEFT OVER VALUE FROM A SHOULD CREATE VECTOR C = [0,0,15]

Answer 1

D = B+C;