Not familiar with psexec, never had to use it. Below code will let you run on a remote machine.
Will need to enable remote execution within qtp as well as dcom settings for it to work.
Set qtApp = CreateObject("QuickTest.Application","XX.X.XX.XXX") 'To run scripts on remote machine ip address
qtApp.Visible = True
If Not(qtApp.TDConnection.IsConnected) Then
qtApp.TDConnection.Connect "http://XXXXXXXXXXXXX/qcbin","Domain", "Project", "userid", "password", False
qtApp.Open "[QualityCenter] Subject\Test1", False
How to Run QTP on other machine without using QC