How do I match value between two column?

No of bus,Pg, Pl,From Line, To Line
1  ,0,  0,  2,  7
2,  1.63,  0,  7,  8
3,  0.85,  0,  7,  5
4,  0,  0,  5,  4
5,  0,  1.25,  4,  1
6,  0,  0.9,  4,  6
7,  0,  0,  6,  9
8,  0,  1,  9,  3
9,  0,  0,  9,  8

above is my dat file name 9bus.dat

i read it in table form.

T = readtable('9bus.dat');
T(1:9,1:5)

How do I point all the value in FromLine to value in Pg? For example.. I want to point No 2 in FromLine to value in Coloumn2-Row2, I want to point all No 7 in FromLine to value in Column2-Row7.

Thank you.