PHP COM encoding problems

Hi everyone, I have quite a problem using a COM-Object in PHP. The COM-Object connects to a database that's UTF-16 encoded and gets text-contents, that I want to process in PHP and write it back using the COM-Object. Unfortunately I cannot connect directly to the database, I have to use that COM-Object. My problem is now, that there seems to be some encoding-problem between the COM-Object and PHP. For example I have a character that looks like an "i" but without the dot. When I read it via the COM-Object, it returns it as a normal "i". I also tried different internal encodings in PHP, but with no effect. When I read the file directly from the filesystem the characters are fine, just as in the file. Also in the database the characters are as they have to be. Does anyone of you know that kind of problems with PHP and COM-Objects and maybe a way to solve it? Greetings