Marco,

I am curious as to why TIB_EditEnh with an appropriate mask definition
is not suitable for this purpose? To experiment with different masks,
drop TEditEnh (non-IBO version) onto a form and click on the EditMask
property editor button. This will display a dialog with sample masks
that you can play with. The dialog provides an edit control with the
mask formatted ready for copy and paste into the FieldsEditMask
property of the dataset or connection (which is the only way of
loading masks into IBO aware controls).

If you still find that you want to derive a new control, you may want
to take a look at the IBC_BitCheck* files (including the .rtf
document) in the IBO source directory. These describe how to do an
IBO derivation that reuses some of the IBO code - making it simpler
and faster to get going.

Geoff Worboys
Telesis Computing