Search Provider to search through non sitefinity database

Hello Everyone,

I am working with Sitefinity V4.3, I am using other database then default Sitefinity database to store custom data.
Now i want to include these data to be part of search module, how can i accomplish this?
Maybe, Do I need to create custom search index for those tables? I dont know how? Or is there any other way, please suggest.

Any help is greatly appreciated.

Thanks,
Abhishek Trivedi