[funkydunk]

are you putting the include in the template? or the database?

it wont parse if you do it in the database.

in the template

something like:

{include_php file="/path/to/load_nav.php"}

ideally the file to load in will be named so as to easily recall it such as being named after the sku.

then you could do:

{assign var="sku" value = $product.productcode}
{assign var="file" value = "$sku.php"}
{include_php file=$file}