Merge columns problem

Hi,

I have 3 columns:

Column 1
A
B
C

Column 2
E
F
G

In Column 3, I want to put formula like track(track, Column1 value, Column2 value)

track is a word of my formula not used in excel.

How should I put Column1 and Column 2 values in my formula? If I drag column 3 automatically Column1 and Column 2 values should change.

Can anyone help me with this...