What is the best way to connect Windows Client to multiple sharepoint versions e.g. 2007, 2010, 2013?

Hi,

I got requirement to develop windows client to manipulate files from different versions of sharepoints servers.

I have successfully connected to Sharepoint 2010 by adding reference in Visual Studio Windows App. I am using SPSite's object to connect with server.

Now customer wants to connect same client with Sharepoint 2007 and 2013 but it(exe) is unable to connect, as reference is not added for these SP versions.

Please suggest me better way so that EXE work with SP 2007,2010 and 2013 versions.

Regards

Deepak Rai

Regards Deepak Kumar Rai Enhanced Software Solution India