Transferring single file type from multiple subdirectories

Is it possible to upload all files with a specific extension up from a variety of subdirectories but not the rest?
e.g. you have a directory, say C:\dir\ with sub-directories of \subdir1, \subdir2, \subdir3. Each of the subdirectories has a variety of file types in it, but you want to use a batch file to only send up the .PNG files from all of the directories?

For the final implementation of this I want to create a batch script to send up the PNG files first, followed by an XML file. Transfer order is important, and the names of the sub-directories the files are in will change.

Thanks in advance,
Moonsail

Alternately, could I do a hack of changing the exclude file type from the command-line? Not finding any documentation about changing the exclusions list from the command-line, so it might not be possible.

Found what I was looking for in the documentation. What I wanted was to use include masks.

Thanks!