Maybe I'm missing something.
I'm looking at the properties for the textbox, on the form.
These are the options I find:
Control Source, Format, Decimal Places, Input Mask (which is >000000LLLL00), default value, IME Hold, IME Mode, IME Sentence Mode, Validation Rule, Validation text, Enter Key behavior (default), Allow Auto Correct, Visible, Display When, Vertical, Enabled, Locked, Filter Lookup, Auto Tab, Tab Stop, Tab Index, Scroll Bars, Can Grow, Can Shrink, Left, Top, Width, Height, Back Style, Back Color, Special Effect, Border Style, Border Color, Border Width, Fore Color, Font Name, Font Size, Font Weight, Font Italic, Font Underline, Text Align, Shortcut Menu Bar, ControlTip Text, Help Context Id, Tag, Before Update, After Update, On Dirty, On Undo, On Change, On Enter, On Exit, On Got Focus, On Lost Focus, On Click, On Dbl Click, On Mouse Down, On Mouse Move, On Mouse Up, On Key Down, On Key Up, On Key Press, Reading Order, Keyboard Language, Scroll Bar Align, Numeral Shapes, Left Margin, Top Margin, Right Margin, Bottom Margin, Line Spacing, Is Hyperlink, Smart Tags
I couldn't find anything like "SelStart" or "SelLength" under properties (on either the txtbox object on the form, or on the properties of the item in the table)
Is there someplace else I need to look?