@echo off
wmic path Win32_PerfFormattedData_PerfProc_Process get Name,PercentProcessorTime | findstr /i /c:w3wp >%temp%\cpu.txt
set /p cph=<%temp%\cpu.txt
for /f "delims=" %%2 in (%temp%\cpu.txt) do set CpuUsage=%%2
set CpuUsage=%CpuUsage:w3wp=%
set CpuUsage=%CpuUsage: =%
rem set "%~1=%CpuUsage%"
echo %CpuUsage%

When I run this dos script from command prompt I get following value :-
30

I have configured ExternalParameterShellExecin on agent configuration file as following :-

#
# NetXMS agent configuration file
# Created by agent installer at Sat May 20 17:52:36 2017
#

MasterServers = netxms.kochartech.com
ConfigIncludeDir = C:\NetXMS\etc\nxagentd.conf.d
LogFile = C:\NetXMS\Log.txt
DebugLevel = 9
AgentCommandTimeout = 40000
FileStore = C:\NetXMS\var
SubAgent = ecs.nsm
SubAgent = filemgr.nsm
SubAgent = ping.nsm
SubAgent = logwatch.nsm
SubAgent = portcheck.nsm
SubAgent = winperf.nsm
SubAgent = wmi.nsm
ExternalParameterShellExec=w3wpcpu:C:\NetXMS\scripts\CpuUsage.cmd

I have restarted the agent. Run Poll full configuration on Node from server console.
When I run following command from server I got blank value
c:\NetXMS\bin>nxget X.X.X.X w3wpcpu

On agent debug log file I got this

[15-Jun-2017 20:57:54.262] [DEBUG] [session:1] Received message CMD_GET_PARAMETER
[15-Jun-2017 20:57:54.262] [DEBUG] [session:1] Requesting parameter "w3wpcpu"
[15-Jun-2017 20:57:54.262] [DEBUG] H_ExternalParameter called for "w3wpcpu" "SC:\NetXMS\scripts\CpuUsage.cmd"
[15-Jun-2017 20:57:54.262] [DEBUG] RunExternal called for "w3wpcpu" "SC:\NetXMS\scripts\CpuUsage.cmd"
[15-Jun-2017 20:57:54.262] [DEBUG] RunExternal: command line is "C:\NetXMS\scripts\CpuUsage.cmd"
[15-Jun-2017 20:57:54.262] [DEBUG] RunExternal (shell exec): worker thread created
[15-Jun-2017 20:57:54.730] [DEBUG] RunExternal (shell exec): execution status 0
[15-Jun-2017 20:57:54.730] [DEBUG] [session:1] GetParameterValue(): result is 0 (SUCCESS)
[15-Jun-2017 20:57:54.730] [DEBUG] [session:1] Sending message CMD_REQUEST_COMPLETED (size 48)
[15-Jun-2017 20:57:54.730] [DEBUG] [session:1] Outgoing message dump:
  ** 001D0000000000300000000200000002
  ** 0000001C000000000000000000000000
  ** 00000015010000000000000000000000
  ** code=0x001D (CMD_REQUEST_COMPLETED) flags=0x0000 id=2 size=48 numFields=2
  ** [    28] INT32    0
  ** [    21] STRING  ""

[15-Jun-2017 20:57:54.746] [DEBUG] [session:1] Message receiving error (MSGRECV_CLOSED)
[15-Jun-2017 20:57:54.746] [DEBUG] [session:1] Session with X.X.X.X closed
[15-Jun-2017 20:57:55.448] [DEBUG] [session:0] Message dump:
  ** 00410000000000300000003700000001
  ** 00000055010000000000000E00770033
  ** 00770070006300700075000000000000
  ** code=0x0041 (CMD_GET_PARAMETER) flags=0x0000 id=55 size=48 numFields=1
  ** [    85] STRING  "w3wpcpu"

[15-Jun-2017 20:57:55.448] [DEBUG] [session:0] Received message CMD_GET_PARAMETER
[15-Jun-2017 20:57:55.448] [DEBUG] [session:0] Requesting parameter "w3wpcpu"
[15-Jun-2017 20:57:55.448] [DEBUG] H_ExternalParameter called for "w3wpcpu" "SC:\NetXMS\scripts\CpuUsage.cmd"
[15-Jun-2017 20:57:55.448] [DEBUG] RunExternal called for "w3wpcpu" "SC:\NetXMS\scripts\CpuUsage.cmd"
[15-Jun-2017 20:57:55.448] [DEBUG] RunExternal: command line is "C:\NetXMS\scripts\CpuUsage.cmd"
[15-Jun-2017 20:57:55.448] [DEBUG] RunExternal (shell exec): worker thread created
[15-Jun-2017 20:57:55.900] [DEBUG] RunExternal (shell exec): execution status 0
[15-Jun-2017 20:57:55.900] [DEBUG] [session:0] GetParameterValue(): result is 0 (SUCCESS)
[15-Jun-2017 20:57:55.900] [DEBUG] [session:0] Sending message CMD_REQUEST_COMPLETED (size 48)
[15-Jun-2017 20:57:55.900] [DEBUG] [session:0] Outgoing message dump:
  ** 001D0008000000300000003700000002
  ** 0000001C000000000000000000000000
  ** 00000015010000000000000000000000
  ** code=0x001D (CMD_REQUEST_COMPLETED) flags=0x0008 id=55 size=48 numFields=2
  ** [    28] INT32    0
  ** [    21] STRING  ""

Kindly help how to resolve the issue and get value on server.