Requirement about matrix(row only)

HI...

A small requirement i need..

Normally we are giving some values into the matrixes..

after loading the values into the matrix..

if we want to disable the particular matrix column by using

omatrix.Columns.Item("V_0").Editable

but my requirement is

i had one matrix on my screen..

it has three columns..

first row first column i put cfl..

if i choose at first row and coulmn --remaining coulmns first row will be filled.

my question is how can i disable the first row only not column....

is it posssible...