On a TextBox,EditBox,Combobox,Spinner if Alignment is not Left,
with:

SelStart = 0
SelLength > 0

the selection area use the TextBox left Margin,
but for me the correct is the .Text Left Margin pixel.

Run this and move with left/right arrow:

PUBLIC oform1

oform1=NEWOBJECT("form1")
oform1.Show
RETURN

DEFINE CLASS form1 AS form

	ADD OBJECT text1 AS textbox WITH ;
		Alignment = 1, ;
		Value = "  ABCD", ;
		Left = 70, ;
		Top = 38

	PROCEDURE text1.GotFocus
		this.SelStart=0
		this.SelLength=1
	ENDPROC

	PROCEDURE text1.Keypress(m.nKeyCode,m.nShiftAltCtrl)
		NODEFAULT
		TextBox::KeyPress(m.nKeyCode,m.nShiftAltCtrl)
		IF INSMODE()
			this.SelLength = 1
		ENDIF
	ENDPROC
	
ENDDEFINE

PS On Excel 2003 this same behaviour is present.
Then, or two bugs or MS have a different opinion respect to me.

Thanks

Fabio