htaccess 301 redirect prestashop

i have a old site written in php and i'm moving customers and products on a new fresh prestashop 1.5.4.1 store. old urls, well linked on search engines, obviously do not match with new product and categories urls so for best linked products I need some kind of 301 redirect on htaccess or with other solution. the problem is that all kind of strings I wrote on .htaccess simply do not work. I need to solve the problem with a correct string that works example of old url syntax redirected to new url: old url syntax [login to view URL] 301 redirected to new url writed so: [login to view URL] ps the new url is friendly url made by prestashop...