Product prices with 5 decimal places in the list of products of the back-end

[dap06]

Hello,
I would like to have the product prices with 5 decimal places in the list of products of the back-end (~ administrator / index.php? Option = & view = com_virtuemart product).

The default.php file (administrator / components / com_virtuemart / views / product) poster $ product-> product_price_display;
I can not change it to display with decimals.

Quelq'un have an idea?

I use Joomla VirtueMart 3.5.1 and 3.0.16

Thank you