How to remove Specific Category name from URL when product is load

Question

Can it possible to Remove Specific Category from URL when Product is Load.

For Example, if Category Name Like this

Product Subject Presenters

1) when we click in Product Category Load all Product and URL generate like this, www.sitename.com/product.html

2) and in this category when we click any one of Product then URL Generate like this www.sitename.com/product/product_name.html

3) but i want URL to generate like this, www.sitename.com/product_name.html

i want to do 3) case, please do some suggestion for this,

i have already tried Use Categories Path for Product URLs = NO but if do this, from another category's name has removed.