InfoPath Dev

At our office, we are using WSS 3.0, IP 2007, and we have some various windows app's.  What I would like to do is create a library in Sharepoint that we will pass data into from Infopath and a windows app.  While I know and can do this with Infopath.  I was wondering if it was possible to use C# to pass data into a Form Library in Sharepoint from a windows app.  Both my Infopath Form and my Windows App would be updating this library.  Is this possible and if so could someone push me in the right direction.  Thank you very much!!!

You could also use SQL if you want to share data between InfoPath and your Web App, it might be a bit simpler.

You should be able to find details on how to setup a web service with your windows applications in C#. That is all it is. SharePoint exposes the web service and in InfoPath you configure how to interact with it.  Also if you look at some of the examples of how to interact with web services via code that would be similar in your windows applications.

 I have found the webservice, and I have been able to pull data from Sharepoint.  I was thinking about updating data in Sharepoint though.  If I have a form published to a library, and I have different columns in the library that contain data in the Infopath form.  I want to be able to update that data in the columns in Sharepoint.  WIll that also update the xml file as well, and is this still possible? Thanks for your help and if you know a good resource on this that would be helpful as well.

I think you are reffering to promoted properties in a document library.  These are promoted from a form when it is saved. I am not sure you can modify them but even if you did they would be out of sync with the form itself. Typically you would update the form, publish, and promoted properties would be updated too.  Could maybe update XML as well but then you might as well submit it and have the promoted properties updated automatically with the builtin functionality. It goes XML to Promoted Properties, not the other way around.

If you want to update list items there are several blogs and posts on how to do that with a CAML.