Windows 7 - Move only files of a given extension while preserving folder structure
You can accomplish this using the Robocopy utility. Robocopy is standard in Windows Vista, Windows 7 and Windows Server 2008. If you have a previous version of Windows, you can get it as part of the Windows Resource Kit for your version of Windows. From a command prompt, use the following command and it should take care of your problem:
robocopy c:\source c:\destination /E *.txt
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