Convert Current Products to Downloadable Products

I am using the latest version of Zen Cart and currently have a large amount of products in my shop - I am now in the position to make the majority of these downloadable products.

Now, I know it is possible to have downloadable product and am aware of how to set the attributes etc up but my question is...... does anyone know of a way that i can bulk update all my existing products to change them to downloadable?

I am hoping there is some kind of workaround as I dont really fancy going thru all of them one by one (and ideally i want to set each product up with multiple file downloads - several different file types for each product)

Anyway any assistance from anyone is as always appreciated.

thanks in advance

Set up one product for downloads, with all the appropriate option names and values.
Then use the attributes copier to copy that product's attributes to all the others.
Then go set up the individual filenames relevant to those products.