After peeking around the internet it looks like it is possible to interop between C# and Matlab. I am wondering if anyone has had success with it and what they did to do so.
Yes, quite possible. Though I ended up using the C interface and calling into that using a mixed-mode DLL (and getting C# to call into that... but that was because I was also interfacing with some other C code). It's quite straightforward. On computers where you want to run your program, you'll need to install Matlab Runtime MCRInstaller.exe.
edit: removed broken link