Looking for some help/guidance on integrating Microsoft Excel with other business applications

Currently we are using Excel to model various business scenarios created and maintained by individual users with their own versions and copies of excel.

Excel is the best application in what its doing, with visible calculations etc. but each  copy is standalone.

What I am looking for is to integrate several copies of excel from various users and save the data in a backend database so that I could use these data further for next level of integration with other business applications.

Basically extending excel to a fully integrated 2-tier or n-tier application.

Wondering if there is any product in Microsoft already that would address this requirement that we could use instead of re-inventing the wheel.

We were thinking of developing a web based application to mimic a spreadsheet but I thought there might be a ready-made product in the market that we could make use of.

Any assistance here is appreciated.