Thanks for your comments. I believe I managed to do what I wanted to do. I splitted the database (mbd-file) in a front and backend and compiled the frondend to a mde-file both with the standard menu functions in MS Access 2003. Before compilation of the frondend I added the code which I found on internet page
http://www.databasedev.co.uk/disable_shift_bypass.html to disable the [SHIFT] key and to create an option for me to enable this key. This database is now running with the runtime of MS Access 2003 which I found on internet page
http://www.rimesrv.net/download.htm.
Like I said I believe this solved my problem, but does one of you see an error in this solution? Secondly, to create an option for me to enable the [SHIFT] key I created a button on the main menu. I thought to be clever and made this button invisible for the user. Then I found this button does not work once it is made invisible. Is this correct and does one of you have an other proposal to create a hidden point to access the backend?