not sure about post, but a get request works pretty well and fast

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Dim strURL As String

strURL = "https://www.scan.com/Tracks.php?uname=" & cboUsername.SelectedItem.key & "&dir=" & cboDirectory.SelectedItem.key

ShellExecute 0, "open", strURL, vbNullString, vbNullString, SW_MAXIMIZE