If you take a look at the SC_Product class:
You will need to append your column name to the list of columns in the following methods:
lists() //line 130 (used for the list page)
alldtlSQL() //line 600 (used for the individual product page)
Once done, it should then be accessible in the template:
Of course, the best method to make these alterations would be to extend the methods in the SC_Product_Ex class rather than editing the SC_Product class directly.