MySQL foreach alternative for procedure

My problem is fairly simple. I have table sets that store product sets (more products looking like one on the outside - computer, mouse and keyboard for ex.) it's connected M:N using sets_products table to products table. Each product can have parameters (connected again M:N).

I have a procedure, that generates all parameters as string (for search cache - like 'hdd:120GB, LCD:1440:900, ..'), but now I need to loop through the set's products and call the procedure for each of them. I CAN'T DO IT IN PHP, because this is used in trigger.

I'd like to use something like this (pseudo SQL)

FOREACH(SELECT products_id FROM sets_products WHERE set_id = 1)
    generate_parameter_list(product_id,@result)
    @param = CONCAT(@param,",",@result);
END FOREACH;

Can this be done in MySQL or not?