I am also not completely sure, what you are looking for,
but if you are looking to build your own effects, there are
these Plugins from Positive Grid, where you can (low complexity tho)
build your own modulation, distortion, delay, eq and compressor.
Each its own plugin.
If you look for more complex options but don´t want to code on the lowest level,
you can use NI Reaktor.
And if you want to code on a pretty low level there would be BlueCat Audios Plug´n´Script
or the developement-tool in Reaper.
But if you are looking for something like an impulse… this won´t work. As @Synthiemental mentioned.
This method only works for Eq-curves and reverbs as I know.