Do you actually need to? Generally you can store .css and .js files in the head using ods headtext (I think there is a stylesheet option for 9.2 as well). Alternatively, store it in a template via proc template. From what I can see in the documentation, using _replay creates multiple calls to the stored process server within a stored process (correct me if I am wrong). The browser is very good at caching stylesheets and javascripts in an optimal way (especially chrome and firefox). I think using template or headtext would result in more efficient browser processing.
If you do want to use it, it looks like you would have to parse the css or js file via a sas stored process and include the full stored process url in your head section of the stored process output anyway.