My Template Button Overrides

In \includes\templates\template_default\sideboxes\tpl_search_header.php, the HEADER_SEARCH_BUTTON is currently extracted from admin\includes\languages\english\images\buttons.

if (strtolower(IMAGE_USE_CSS_BUTTONS) == 'yes') {
$content .= zen_draw_input_field('keyword', '', 'size="6" maxlength="30" style="width: 100px" value="' . HEADER_SEARCH_DEFAULT_TEXT . '" onfocus="if (this.value == \'' . HEADER_SEARCH_DEFAULT_TEXT . '\') this.value = \'\';" onblur="if (this.value == \'\') this.value = \'' . HEADER_SEARCH_DEFAULT_TEXT . '\';"') . ' ' . zen_image_submit (BUTTON_IMAGE_SEARCH,HEADER_SEARCH_BUTTON);
} else {
$content .= zen_draw_input_field('keyword', '', 'size="6" maxlength="30" style="width: 100px" value="' . HEADER_SEARCH_DEFAULT_TEXT . '" onfocus="if (this.value == \'' . HEADER_SEARCH_DEFAULT_TEXT . '\') this.value = \'\';" onblur="if (this.value == \'\') this.value = \'' . HEADER_SEARCH_DEFAULT_TEXT . '\';"') . '&nbsp;<input type="submit" value="' . HEADER_SEARCH_BUTTON . '" style="width: 45px" />';
}

However, for consistency I want to use the buttons of my template, ie \includes\templates\MyTemplate\buttons\english. How do I do this?

Similarly, in \includes\templates\template_default\templates\tpl_advanced_search_default.php, I want the TEXT_SEARCH_HELP_LINK, as in

<div class="forward"><?php echo '<a href="javascript:popupWindow(\'' . zen_href_link(FILENAME_POPUP_SEARCH_HELP) . '\')">' . TEXT_SEARCH_HELP_LINK . '</a>'; ?></div>

to also be a button from my template rather than the plain text.

TIA