if you com object is single threaded, then in asp.net core you would run it a dedicated thread (see background service). then you would use messages to send a request / response to the com object.
to implement messages, you could use blocking collections. you could also just have static request/response variables, and use locking and a mutex.
another option is create a node app that hosts the com object. the you new asp.net app would use httpclient to call the api. you could write a simple c++ wrapper, but node is single threaded, so this is nothing special. or try:
https://github.com/idobatter/node-win32ole
if you might also look at updating your com object to a single threaded apartment model and create on a STA thread.
https://learn.microsoft.com/en-us/windows/win32/com/single-threaded-apartments