Unfortunately, the technique described by Anders turns off all the built-in menus.
Each form also has a method that allows you to block shortcut menus, you can set "Shortcut Menu" = No, but again that blocks all shortcut menus on a form. To overcome this, you can use the MouseUp event, check for the right click, and then use the commandbars ShowPopup method to display your menu.
Another alternative would be to use the Form Open and Form Close event to disable/enable specific commandbars:
CommandBars("form datasheet row").Enabled = False
but you will need to know the name of the commandbars you want to disable, and need to make sure you enable them again on form close or they will not show up on other forms either. To do this, you will need to know the name or index of the commandbar, if you download the Access Shortcut Tool, it will provide that information.
Clive