Have you tried it with the Options dialog box open?
I tried this with the box open and it works:
select case OptionsDlg.DesignDlg.LineTraceAngle
case 0
OptionsDlg.DesignDlg.LineTraceAngle = 2
case 2
OptionsDlg.DesignDlg.LineTraceAngle = 0
end select
I did not try to "apply" the setting or assign the macro to a hot key... but I do see the radio button change.