Naturally I figured it out shortly after I created this post :) For those like me who aren't great with VB, I used a sample script from this page and tweaked it like so:
'Gather registry key value from machine and posting data to NS using Altiris NSE Component
'===================================================================================================================
' On Error Resume Next
const HKEY_LOCAL_MACHINE = &H80000002
strComputer = "."
Set oReg=GetObject( _
"winmgmts:{impersonationLevel=impersonate}!\\" &_
strComputer & "\root\default:StdRegProv")
strKeyPath = "SOFTWARE\XXXXXX\BuildInfo"
strValueName1 = "freshnessdate"
strValueName2 = "site"
strValueName3 = "Win_7"
strValueName4 = "Win_XP"
oReg.GetStringValue _
HKEY_LOCAL_MACHINE,strKeyPath,strValueName1,freshnessdate
oReg.GetStringValue _
HKEY_LOCAL_MACHINE,strKeyPath,strValueName2,site
oReg.GetStringValue _
HKEY_LOCAL_MACHINE,strKeyPath,strValueName3,buildversion7
oReg.GetStringValue _
HKEY_LOCAL_MACHINE,strKeyPath,strValueName4,buildversionxp
'WScript.Echo "Request ID: " & freshnessdate
'WScript.Echo "Computer Description: " & site
if isnull(freshnessdate) then
freshnessdate = "missing"
end if
if isnull(site) then
site = "missing"
end if
if isnull(buildversion7) then
buildversion7 = "missing"
end if
if isnull(buildversionxp) then
buildversionxp = "missing"
end if
'===================================================================================================================
'Create instance of Altiris NSE component
dim nse
set nse = WScript.CreateObject ("Altiris.AeXNSEvent")
' Set the header data of the NSE
' Please don't modify this GUID
nse.To = "{1592B913-72F3-4C36-91D2-D4EDA21D2F96}"
nse.Priority = 1
'Create Inventory data block. Here assumption is that the data class with below guid is already configured on server
dim objDCInstance
set objDCInstance = nse.AddDataClass ("{PUT YOUR DATACLASS GUID HERE}")
dim objDataClass
set objDataClass = nse.AddDataBlock (objDCInstance)
'Add a new row
dim objDataRow
set objDataRow = objDataClass.AddRow
'Set columns
objDataRow.SetField 0, buildversion7
objDataRow.SetField 1, buildversionxp
objDataRow.SetField 2, site
objDataRow.SetField 3, freshnessdate
nse.SendQueued