Send Info to Excel with Option Strict On

I have an application that sends information to Excel.  It works fine if I have Option Strict Off.  However, I am required to turn Option Strict On.  When I do, I get "late binding" errors.  How can I clear up statements such as these?  (All give the late-binding error.)

    oSheet.Rows("2:2").Select()
    oSheet.Rows("1").EntireRow.Font.Underline = True
    oSheet.Columns(1).EntireColumn.Style = "Comma"
    oSheet.Columns(1).EntireColumn.NumberFormat = "mm/dd/yyyy"
    oSheet.Columns(1).EntireColumn.HorizontalAlignment = Excel.Constants.xlLeft

Thanks,
ChrisStart Free Trial