Thanks Sergey, works a dream in my app and managed to create a parameter to take the file name in each case and auto open it in the app.

My only issue now is with multiple files, it appears that only a single file can be used this way with my current app. My idea was to write another app which manages and writes each of the files right clicked to a list that can then be picked up and launched by my program, can't see any other way of changing the one instance per file behaviour.

Many thanks for getting back to me on this, your assistance is greatly appreciated.

All the best,

Simon