How to input first column in data table?

hello everyone i very new in matlab, so i want to know that how to insert first column in my data.

My data is a file that in clude 861*2 number for my result it be like

0 0

0 1

0 2

0 3

so i want to include two column in front like this below

Grid 1 0 0

Grid 2 0 1

Grid 3 0 2

Grid 4 0 3

thank you