如何在wordpress中的do_shortcode中添加post meta标签

I'm using Coupon Creator and I like that it comes with the categories and shortcodes. I am using a category shortcode like this example [coupon couponid="loop" category="Brumby's Bakery" couponorderby="date" coupon_align="cctor_alignnone" name="Coupon Loop"].

I wanted to use different category shortcode for each page. Therefore, I kinda created a custom meta box for that (Wordpress Meta Boxes) and called it in the php template page with <?php echo get_post_meta($post->ID, 'couponshortcode', true); ?>. However, the shortcode won't work in php template page unless I use <?php echo do_shortcode('[coupon...]'); ?>

In the end this code which was supposed to be like that wouldn't work because of php in php.

<?php echo do_shortcode(<?php echo get_post_meta($post->ID, 'couponshortcode', true); ?>); ?>

How do I rework this php code? The only thing I could think of is to use something like var but I don't know how to make it work in php template page.

var $store = <?php echo get_post_meta($post->ID, 'couponshortcode', true); ?>
<?php echo do_shortcode($store); ?>

No need to echo get_post_meta(). This should work:

<?php echo do_shortcode(get_post_meta($post->ID, 'couponshortcode', true)); ?>