Take a look at 'RandomReset()':
Names Default To Here( 1 );
nr = 10;
nc = 10;
mat = J(nr, nc, .);
for (c=1, c<=nc, c++,
Random Reset( 1 );
mat[0,c] = J(nr, 1, RandomUniform());
);
dt1 = AsTable(mat);
dt1 << setName("Columns the same");
for (c=1, c<=nc, c++,
Random Reset( 666 );
mat[0,c] = J(nr, 1, RandomUniform());
);
dt2 = AsTable(mat);
dt2 << setName("Columns the same");