I had some problems finding the correct syntax for this process, so now I have successfully found it I thought I’d share it:
On a Mac: moviemac:/path_to_your_file
On Windows: moviewin:/path_to_your_file
Oh and why might you want to do this? Because if you use the Insert File, Insert Picture or Insert Quicktime Script steps you have to specify a file path manually rather than doing so via a calculation, which is very inconvenient if you need to import say: 3,500 files as needed to.
If you use the Set Field Script Step and specify the appropriate Container Field, with the new contents being your Calculated File Path Field then you can effectively side step this problem. I only need to do this as a temporary measure so it’ll work just fine for my purposes.
If you’re looking for something more permanent you’d have to think about whether or not it stores the file as reference or actually inserts it, which makes a big difference and the answer to which I don’t know (if you DO know or find out please tell us in the comments).