Are you trying to change the instance name or the actual file name?
Im trying to change the actual file name, change the link reference of video. Change power.f4v to test.f4v with lingo.
Someone can correct me but I believe member is only an instance of the original file (or filename).
I use BuddyAPI Xtra to perfom file management activies. You can do error checking for the process too for many of the file commands using the code the command returns.
BuddyAPI Doc's Excerpt:
Platform: Windows and Macintosh
Description: baRenameFile renames a file or folder.
Usage: Result = baRenameFile( FileName , NewName )
FileName is the file to rename.
NewName is the new name for the file.
Returns 1 if the file was successfully renamed, else 0.
set OK = baRenameFile( "c:\data\student.dat" , "c:\data\student.bak" )
Notes: This function will fail if a file called NewName already exists. The full path name to
both the FileName and the NewName should be given. You can use this function to
move a file to a different folder, providing it is on the same drive. You can also
See also: baFileExists
Also here's a site list of Xtra's
Which #type of member is "vidcontainer"?