In theory
FileName = folderPath & Item.Subject & Right(Attach.FileName, InStrRev(Attach.FileName, Chr(46)))
However there are some things to consider when approaching this issue.
What do you want to do about illegal filename characters in the subject.
What do you want to do if there is more than one attachment.
What do you want to do if the filename already exists in the target folder.

See http://www.vbaexpress.com/forum/show...ll-attachments