OpenEuphoria

Are you thinking of something along the lines of RegEx? I use this a lot when importing data from text files. For me it is less important to have automatic formatting in text boxes since we try to avoid manual input as much as possible. My work has largely been to automate bulk data transfers/conversions and manual updating of data is permitted only when deemed necessary.

We generally deal with long lists of data or transactions in a ListView. I used to display error messages in a message box but for the volumes of data we deal with I found it more practical to add an additional column to the ListView and use that for error messages.