File Copy and re-name file question.

I am writing a bit of code and I need a sub that will execute a file move for me and if there is a duplicate I want to move it to a different folder and rename it.

The process will be used over and over so it is possible that a file that has previously been processed will be processed for a second time. This is what I want to trap.

Lets say that the start folder is C:\RawFiles
And the end folder is C:\ProcessedFiles
And the error folder is C:\ErrorFiles

Under normal circumstances I want to move files from C:\RawFiles to C:\ProcessedFiles but if the file name already exists in C:\ProcessedFiles then I want to move it to the C:\ ErrorFile folder

Lets say the file is TestMessage.msg

NO DUPLICATE FILES
1.Check if a file called TestMessage.msg exists in the folder C:\ProcessedFiles
If not then Move C:\RawFiles\TestMessage.msg to C:\ProcessedFiles\TestMessage.msg

DUPLICATE FILES
2. If a file called TestMessage.msg exists in the folder C:\ProcessedFiles
Then make a copy of the file thats already been processed in C:\ProcessedFiles in the folder C:\ErrorFiles but rename it DF0-TestMessage.msg
i.e. the file will become C:\ErrorFiles\ DF0-TestMessage.msg    DF0 = Duplicate File 0

3. If a file called C:\ErrorFiles\DF0-TestMessage.msg already exists the folder C:\ ErrorFiles then do not make a copy of the file in the C:\ErrorFiles folder

4. Move the file C:\RawFiles\TestMessage.msg to C:\ErrorFiles but rename it C:\ErrorFiles\DF1-TestMessage.msg

5. On the off chance that we already have a C:\ErrorFiles\DF1-TestMessage.msg file in the C:\ErrorFiles folder then rename the file C:\ErrorFiles\DF2-TestMessage.msg or C:\ErrorFiles\DF3-TestMessage.msg and so on.

Thanks for your help