With few typo fixes:

LOCAL oExcel as Excel.application

oExcel = CREATEOBJECT([Excel.Application])
oExcel.WorkBooks.Add()
oExcel.range('A1').value  = [Test Superscript more text]
With oExcel.ActiveCell.Characters(1, 5).Font
        .Name = "Arial"
        .FontStyle = "Regular"
        .Size = 10
EndWith

With oExcel.ActiveCell.Characters(6, 11).Font
        .Name = "Arial"
        .FontStyle = "Regular"
        .Size = 10
        .Superscript = .t.
    ENDWITH
oExcel.Columns.AutoFit()  
oExcel.visible = .t.

>Don,
>Based on Naomi's macro
>Not tested because I have no MS Office installed on my computer, so maybe I am completely wrong.
>Unfortunately MS Office 2007 can't be installed on Server OS with Terminal services turned ON.