Custom Field Urls

Hello, sorry for my english.

is there any way to change the url of a custom field to make it friendly?
Ex: In my site make available some zip files through custom code field “<? Php echo get_post_meta ($ post-> ID, ‘custom_field_archive’, TRUE);?>”

But the url at the end of the download is very large ( filename. zip)

is there any way to turn this into something above link as “”??

got it through the plugin wp-download manager, however my site has over 2,000 posts. Each of them has a CF. Would be impossible to create a custom url for each manually.
Is there any way to automatically create these urls? Through httacess or some script? this would be possible?