xcopy help

is there any way to use the xcopy or another command to copy files from a pc based on file extension and not retian the file structure when puting them in the destination.  would like to copy all files from one computer with the same file type to one directory without making all of the file structure sub-directories.

If the directory structure is stable and known, you could use a batch script to copy from each directory to a single destination. Otherwise, xcopy is designed to copy the file tree along with the files to a destination.