files disappearing

In another post, a member mentioned that to do a SetFileAttributes() without
clearing the rest of the attributes... that I could do this:

SetFileAttributes (filename, GetFileAttributes(filename)&~FILE_ATTRIBUTE_READONLY);

evidently it is the '~' that makes the difference here.

Removing the ~ mark will set whatever attribute I need to ON, however it will reset the others to OFF...

Adding the ~ mark however.... seemingly makes the file disappear from time itself, but it still exist in a parallel dimension because a "dir /all" shows it still there... but it is missing from explorer..(no its not hidden either)...missing from a regular "dir"....missing from file searches ect...

My questions are these:

1. Why are these files disappearing, and how do I a) get them back or b) remove them?

2. Since this way is obviously inadequate, how might one set attributes without resetting all the others?

Regards,

- Mac