problem with DiskFree with cdr's

given the following code...

__int64 AmtFree = DiskFree(0);
__int64 Total = DiskSize(0);
AnsiString S;
S.sprintf("%I64d percent of the space on drive 0 is free: %I64d KB", AmtFree*100/Total, AmtFree/1024 );

This works fine with fixed disk and cdrw's with drag and drop... basically
any disk with a file system on it...

what I'm looking for is a way to get this diskfree and disktotal from a
cdr that had not been closed yet...

thanks,

That's not even remotly possible. Dude, if the CDR is open, the CD can't even be read, so how could the computer find that out?