Add query language to an app. Ish.

Hi everyone, looking for a bit of advice from someone who might have done something similar before. We have a large and stable application that in its broadest term is an accounting package. It has a well defined business model, business objects are set up, data is stored and it all works fine. We have generic report functionality that allow our users to generate reports based on a fixed set of options that we have programmed in to it.

Initially we thought it would be possible to write a form system where users are presented with a series of dropdown boxes that guide them through the process. However, we'd like to offer more flexibility and give the users the chance to "query" the system themselves. On our Alpha system, we use "Layout Files" which is essentially code, which is interpreted by the system and then retrieves the data they requested. Since our users are familiar with this method (and aren't scared of writing a little "code") we'd like to do something similar in the Windows app and thought that some people might have done something similar. In the broadest possible sense we'd like our users to be able to create sets of "queries" in a pseudo-code, e.g.,

"Show me ClientName where ClientName Is whatever and .... " etc. They would need to be able to access our business objects, and the interpreter will need to know what data is available and so on.

I've looked at a few off-the-shelf "rules management" packages, but we can't really tie ourselves in to a package like that as we'd be dependent on it. I've then been looking into VSTA which seems to offer this functionality and since its Microsoft ought to have reasonable support.

I know this all seems quite vague, but I was wondering if anyone had any general thoughts on this sort of concept Thanks.