The DNG Converter is a stand alone application, Lightroom does not use it. You have to first download the raw files from your camera (the one which is not supported by LR 4.4) to the HDD on your computer. If you have already installed the DNG Converter you can then open the application and a dialog box will appear. Select the "Folder" (not the files themselves) where the raw files are located and choose the other options you wish and proceed to convert to dng. Its best to retain copies of your original files.
After the conversion you will be able to import the dng files with LR 4.4.
Have a look at the following thread for the pros and cons of DNG format. Should I convert to DNG?
Thanks DdeGannes - the work around worked. Good news.
Not the smooth Workflow I'm used to. Bad news
Guess the alternative to this method is upgrading to Lightroom CC for £100 a year. Not what I wanted to do, but they'll find a way to have you over a barrel.
There is also the option to upgrade to LR 6 (perpetual license version.)