ActiveX component can't create object

Below code I;m trying to execute from excel macro. I have addes all required references. during execution getting error ActiveX component can't create object for line

"Set TestCompleteApp = CreateObject("TestComplete.TestCompleteApplication") "

Dim pn As String, un As String, rn As String

pn = "DigiStyle_App" un = "login_test1" rn = "loginApp"

Set TestCompleteApp = CreateObject("TestComplete.TestCompleteApplication")

' Obtains the integration object

Set IntegrationObject = TestCompleteApp.Integration

' Opens the project suite

IntegrationObject.OpenProjectSuite ("C:\Users\s.amin\Documents\TestComplete 10 Projects\DigiStyle1\DigiStyle1.pjs") ' Runs the routine

IntegrationObject.RunRoutine(pn, un, rn)