You can use a script like the following as a field's custom Keystroke script:
// Custom Keystroke script
if (event.commitKey == 2) {
getField("Text2").setFocus();
}
where "Text2" is the name of the next field in the tab order. This can be cumbersome to do for fields that are formatted since they use a built-in keystroke script, but that can be dealt with.