i´m not sure i understood your post correctly, but i think you want that a user clicks on a button/link to open a word-doc that is not opening in ie.
so perhaps that what you need:
header ("Content-type: application/msword");
header ("Content-Length: " . $INT_length);
header ("Content-Disposition: outline; filename=" . $filename);
the important thing is to use "outline"!
cu
chris