Hi Try with this
Dim qcConnection as Object
strQCServer=something
strQCPassword = something
strQCUser = something
Set qcConnection = CreateObject("TDApiOle80.TDConnection")
qcConnection.InitConnectionEx strQCServer
qcConnection.Login strQCUser, strQCPassword
This was executed perfectly on my envi.
I would like you to check whether QC or ALM components and TD connect was installed on this machine.