I found a way to get it done but I am not very happy with this procedure. Please add your answer if you find better way. Mean while, this might be of help.
add_action('admin_head-edit.php','addCustomImportButton'));
I only need this on edit page, so I am using admin_head-edit.php action, but you can use admin_head or some other (not very specific requirement)
/**
* Adds "Import" button on module list page
*/
public function addCustomImportButton()
{
global $current_screen;
// Not our post type, exit earlier
// You can remove this if condition if you don't have any specific post type to restrict to.
if ('module' != $current_screen->post_type) {
return;
}
?>
<script type="text/javascript">
jQuery(document).ready( function($)
{
jQuery(jQuery(".wrap h2")[0]).append("<a id='aspose_doc_popup' class="add-new-h2">Import</a>");
});
</script>
<?php
}