There is no such key.
If you are using a later version of MS Word then open the document and select "Save As". In the file type selection box click on the down arrow to show what file types you can save the document as. Select pdf. Then Save. The pdf version will be then saved in the location you have selected. You may lso have a pdf printer installed. This is a virtual printer to which if you print the document, will do the conversion. If you don't have a pdf printer download Cutepdf from the internet. It has a free version and the earlier versions are much simpler to use and fulfil all the requirements without complicating the issues.