How to use COM

Hi all again, i' am a very bloody greenhorne with php and maybe i have many questions. Heres one another: Who can exlpain to use com in php. How can i execute methods and read attributes? I only know how i can craete an object: $object = new ("adodb.recordset") for exsample, is it not so? But how can i get the attributes and execute the methods? And why the Documentation speaks from com_load,com_invoke and so on. No once of them are working. I only get the message: Call to undefined function.... and so on.. Thanks for Help, Thomas