Passing objects as arguments in VBScript - performance

Question

I'm working on a project to capture various disk performance metrics using VBScript and would like to use a sub procedure with an object as an argument. In the following code samples the object I'm referring to is objitem.AvgDiskQueueLength which will provide a value for the disk queue length. I haven't found a way to make it work since it is recognized as a string and then doesn't capture the value. My goal is to make it easy for anyone to change the counters that are to be captured by only having to make a change in one location(the procedure call argument). The way I'm going about this may not be the best but I'm open to suggestions. The sub procedure call is below.
PerfCounter "Average Disk Queue Length", "disk_queueLength", "objItem.AvgDiskQueueLength"
The following code is the sub procedure.
Sub PerfCounter(CounterDescription, CounterLabel, CounterObject)
Set colItems = objWMIService.ExecQuery("SELECT * FROM Win32_PerfFormattedData_PerfDisk_PhysicalDisk",,48)
args_index = args_index + 1
arrCriteria = split(command_line_args(args_index),",")
strDriveLetter = UCase(arrCriteria(0))
intCriticalThreshold = arrCriteria(1)
intWarningThreshold = arrCriteria(2)
For Each objItem in colItems
With objItem
WScript.Echo "objitem.name = " & objitem.name
If InStr(objItem.Name, strDriveLetter & ":") > 0 Then
intChrLocation = InStr(objItem.Name, strDriveletter)
strInstanceName = Mid(objItem.Name, intChrLocation, 1)
End If
If strDriveLetter = strInstanceName AND InStr(objItem.Name, strDriveLetter & ":") > 0 Then
If intActiveNode = 1 OR Len(intActiveNode) < 1 Then
WScript.Echo "CounterDescription = " & CounterDescription
WScript.Echo "CounterLabel = " & CounterLabel
WScript.Echo "CounterObject = " & CounterObject
If CInt(CounterOjbect) => CInt(intCriticalThreshold) Then
arrStatus(i) = "CRITICAL: " & strDriveLetter & ": " & CounterDescription
arrTrendData(i) = CounterLabel & "=" & CounterObject
intExitCode = 2
arrExitCode(i) = intExitCode
ElseIf CInt(CounterOjbect) => CInt(intWarningThreshold) AND CInt(CounterObject) < CInt(intCriticalThreshold) Then
arrStatus(i) = "WARNING: " & strDriveLetter & ": " & CounterDescription
arrTrendData(i) = CounterLabel & "=" & CounterObject
intExitCode = 1
arrExitCode(i) = intExitCode
Else
arrStatus(i) = "OK: " & strDriveLetter & ": " & CounterDescription
arrTrendData(i) = CounterLabel & "=" & CounterObject
intExitCode = 0
arrExitCode(i) = intExitCode
End If
Else
PassiveNode CounterDescription, CounterLabel
End If
End If
End With
Next
i = i + 1
ReDim Preserve arrStatus(i)
ReDim Preserve arrTrendData(i)
ReDim Preserve arrExitCode(i)
End Sub

Answer 1

Why cant you do this...
PerfCounter "Average Disk Queue Length", "disk_queueLength", objItem.AvgDiskQueueLength

Answer 2

To pass an object you have to pass an object, not a string. To make this method work as expected you would have to have the object prior to the procedure call, but in your code example it looks like you are trying to pass an object that you don't have. A working example:
Set objFSO = CreateObject("Scripting.FileSystemObject")
UseFileSystemObject objFSO
Sub UseFileSystemObject( objfso)
'Now I can use the FileSystemObject in this procedure.
End Sub
But calling the UseFileSystemObject procedure like this will not work,
UseFileSystemObject "objFSO"
because you are passing in a string not an object.
The only way I can think of to accomplish what you want is to use a select statement to write the appropriate attribute of the object, something like this.
Call PerfCounter "Average Disk Queue Length", "disk_queueLength", "AvgDiskQueueLength"
Sub PerfCounter(CounterDescription, CounterLabel, CounterObjectAttribute)
Set colItems = objWMIService.ExecQuery("SELECT * FROM Win32_PerfFormattedData_PerfDisk_PhysicalDisk",,48)
For Each objItem in colItems
Select Case CounterObjectAttribute
Case "ObjectAttribute1"
Case "ObjectAttribute2"
Case "AvgDiskQueueLength"
Wscript.Echo objItem.AvgDiskQueueLength
End Select
Next
End Sub
So in the select you would have to add a case for each attribute that can be used, but it would allow you to pass a string into the procedure. I might be way off on this, but I don't know how you can pass an object if you don't have the object first.