Here are 2 example snippets I use when I have multiple parameters.
'**********************************
' Use this method when I have to put a parameter in ""
mid = """C:\Program Files\FormFlow\Uninst.isu"""
strRemove = "C:\WINDOWS\IsUninst.exe -f" & mid & " -s -a -s"
RemoveOldVer (strRemove) 'Sample RemoveOldVer below
'****************************************
'Use this when all you have to deal with are spaces
InstallIt ("msiexec.exe /I " & SrcDir & "\AccelioCaptureAdvancedEndUserComponents.msi REMOVE=ALL /qb"

'*****************************************
'Sample RemoveIt
Sub RemoveOldVer (strRemove)
Dim Exec, oExec
Exec = strRemove
Set oExec = oWsh.Exec (Exec)
Do While oExec.Status =0
Wscript.Sleep (100)
Loop
Set oExec = Nothing
End Sub
'*****************************************
'Sample InstallIt
' This varies depending upon whether I can use Exec or have to use Run
Sub InstallIt(n1)
Dim ExecStr, oExec
ExecStr = n1
' InstallIt = oWsh.Run (ExecStr , 1, True)
Set oExec = oWsh.Exec(ExecStr)
Do While oExec.Status =0
Wscript.Sleep (100)
Loop
Set oExec = Nothing
End Sub
'Good Luck