Retrieve Form Data from database other than SQL

I have created a group of Forms Using Version 8 pro. that I will be distributing to clients with Adobe Reader. I will also be providing the client with an application that collects and provides them with most of the data required to complete the forms. I could easily produce a text file or even an XML file containing this information. Is there a way to automatically use one of these types of files to complete forms using reader.

I would like it to work as follows:
User runs custom app to generate data.
Custom app creates text or XML file
User selects Adobe Form from list in custom app
Adobe Reader displays Form with data from custom app.

Is this a posibility, If so where can I find some instruction or example code.

I have a book "Extending Acrobat FORMS wit javascript" it states that this could be done using SQL but does not mention anything else. It was however written in 2003. I hope there are other options in 2007

Thanks