try this,
Add JavaScript in your page.
<script type="text/javascript">
function hideColumn() {
var gridrows = $("#GridView1 tbody tr");
for (var i = 0; i < gridrows.length; i++) {
gridrows[i].cells[1].style.display = "none";
}
return false;
};
</script>
cells[1]
instead of you can use your column number.
and call this function on OnClientClick="Javascript:return hideColumn();"
event.