Row Shifting Macro

This is far too complicated for me to program.

Ideally, if at all possible, I want a macro that will align every row of my data by the cell which has the value closest to 20. i.e.

8 10 12 14 16 18 20 22 24 26 28 30
9 12 15 18 21 24 27 30 33 36 39 42
5 10 10 10 12 10 14 50 54 59 62 72
1 10 40 42 44 46 48 50 56 48 62 70

would become...

8 10 12 14 16 18 20 22 24 26 28 30
........9 12 15 18 21 24 27 30 33 36 39 42
5 10 10 10 12 10 14 50 54 59 62 72
.....................1 10 40 42 44 46 48 50 56 48 62 70

As you can see, it looks quite tricky.
If it's too complicated, I can do it by hand (very time-consuming) and a simple macro button would help. I'd need something that will select the whole row of the active cell, and shift it all one space to the right. I'd have another button doing it to the left.