Instead of initiating and using the IE object, why not try using a simple web query instead. The following code may work.
VBA Code:
Sub Login_WebQuery() Dim MyPost As String Const MyUrl As String = "https://www.btwholesale.com/siteminderagent/forms/login.fcc" Const PostUser As String = "USER=" & Worksheets("Login Data").Range("C5").Value Const PostPassword As String = "&PASSWORD=" & Worksheets("Login Data").Range("D5").Value
MyPost = PostUser & PostPassword
With ActiveSheet.QueryTables.Add(Connection:= _ "URL;" & MyUrl, Destination:=Cells(1, 1)) .PostText = MyPost .BackgroundQuery = True .TablesOnlyFromHTML = True .Refresh BackgroundQuery:=False .SaveData = True End With