Hilmar,
You could check the following download#1110, download#0806 and download#93903.
I don't know if they provide the functionality you want, but I guess it would be much easier to adjust one of these classes than create one from scratch.

HTH
>Users typically input lots of numbers with the numeric keypad, but when the Control Panel defines the decimal "point" as a comma, the point is not accepted. This is awkward for quick data entry.
>
>Does anyone have a satisfactory solution for this? I want to continue using SET SYSFORMATS ON. I think several approaches are possible in theory, including a) temporarily changing SET POINT for the control that has the focus (how?), b) converting commas to points in .KeyPress().
>
>TIA, Hilmar.