Manually setting seed for random sorting with SphinxSE?

I need to do a Sphinx query with pseudo-random sorting. To be able to get repeatable results, I'd like to be able to provide a seed that I define to the random function. But I can't seem to find any documentation for doing this with SphinxSE (the MySQL engine). I found in the docs that you can do this using SphinxQL via OPTION rand_seed. What would be the equivalent in SphinxSE? So far I could only figure out sort=extended:@random; which gets automatically seeded.