[modeller_usage] Phosphoserine residue

I am just getting started with Modeller, but I need to incorporate a phosphoserine residue, which Modeller cannot seem to handle by default. I have read the FAQ entry on defining new residue types, but it seems quite daunting and I do not have easy access to the needed software. I see that ten years ago, someone ran into the same problem, but as far as I can tell it was never resolved: http://salilab.org/archives/modeller_usage/2002/msg00177.html

So I will ask the same question as that poor soul a decade ago: does anyone have the appropriate files for phosphoserine, and would be willing to share?

Thanks, Mike Bramson