Around the same time, I added a scripting language to a complex desktop app. My initial prototype just used SIOD [1], but my boss took one look at it and told me to think again, that our customers would never accept having to use a lisp to script the application. I ended up using the VARIANT type heavily (this was on win16), leaning on OLE automation, and building something with C syntax and modules. No first class functions, no prototype object model. :(
[1] https://en.wikipedia.org/wiki/SIOD