How to turn custom field it into a php variable?

Long story short I need to make this work, but tried everything with no luck. Basically I need to use the custom field as a variable, but the below code does not work:

$test = wpsc_cf_get_value('slug=<strong>URLHERE</strong>');

All in all the part I need this for is a shortcode:

echo do_shortcode('[pro-player]<strong>URLHERE</strong>[/pro-player]');

But inserting the code between the shortcode tags renders is as a plain text, not a php variable.

Thanks in advance! `

https://www.ads-software.com/plugins/wp-e-commerce-custom-fields/