I wrote a KB for doing something similar with Dell DTK. The steps are below. You should be able to adapt them to fit the HP tools.
Here are the steps for generating the WinPE image.
1. The following steps must be performed on a Windows-based Workstation.
2. Some antivirus programs can interfere with the WAIK components detailed below. It may be necessary to disable Antivirus software when building WinPE images.
3. Go to Dell.com and search for DTK 2.5 and download the executable.
4. Extract DTK 2.5 using default settings or a directory of your choice.
NOTE: The Dell DTK is only configured to support x86 platforms. The configuration scripts supplied by Dell do not make a distinction for x64 based WinPE images. It may be possible for users to enhance the scripts for x64 support but that task is beyond the scope of this document.
5. Download the Microsoft Windows Automated Installation Kit (AIK) for Vista from the Microsoft Download site.
6. Install MS Windows AIK using default settings. It is not recommended that you alter the default install path for WAIK as this is known to cause issues.
7. Download and Install MSXML 6.0 from the Microsoft Download site. MSXML 6.0 is required for WAIK.
8. Backup the contents of C:\Program Files\Windows AIK\Tools\PETools. This folder contains the original and unaltered WinPE images from Microsoft. Subsequent steps in this procedure will heavily modify the images and a backup is required in cases where rollback is necessary.
9. Download and extract the BMC BladeLogic “Provisioning External Files” pack. This file can be obtained on HYPERLINK "http://www.bladelogic.com/support"www.bladelogic.com/support in the downloads section. Please be sure to download the pack that corresponds to the core release that you are running (i.e. BladeLogic 7.4.5, etc). A valid BMC BladeLogic Support ID and current Maintenance agreement is required to access the download site.
10. Navigate to the directory where you extracted the “Provisioning External Files” pack. Copy \provisioning\winpe\CreateWinPE2_0.Bat and extractpxeboot.bat into C:\Program Files\Windows AIK\Tools\PETools
11. Open a command prompt and CD to C:\Program Files\Windows AIK\Tools\PETools.
12. Execute pesetenv.cmd
13. Navigate to the directory where you extracted DTK 2.5 and drill down into Dell\Drivers\winpe2.x folder.
14. Open VPE_driverinst.bat in any suitable text editor
15. Comment out Step 11 in the script. The line to comment out should include a reference to peimg.exe /prep.
NOTE: Once an image is “prepped” it can no longer be modified. Since BMC BladeLogic will run additional configuration scripts on the image the “prep” step must be skipped. If this step is not skipped subsequent steps in this procedure will fail.
16. Open a command prompt and execute VPE_driverinst.bat C:\winpe20_2950 C:\Dell\Drivers
NOTE: The first argument is a folder where the batch script will place the resulting WinPE image with integrated Dell drivers and utilities. If this folder does not exist you MUST first create it manually. The second argument is the path to Dell\Drivers. This step may run for several minutes and will produce a verbose output.
17. At this point new “winpe.wim” image files have been created in C:\winpe20_2950 or whichever directory path was used in step 16.
18. Copy C:\winpe20_2950\winpe.win to C:\Program Files\Windows AIK\Tools\PETools\x86. This will overwrite the default Microsoft winpe.wim. Moving forward, any new WinPE images will use the Dell modified winpe.wim as a starting point. This way, the Dell integrated tools and drivers will always be present and accessible from inside WinPE.
19. Launch and login to the BMC BladeLogic Provisioning Manager GUI.
20. Browse to ToolsImage Creation
21. Follow the standard BMC BladeLogic Instructions to create, configure and post a WinPE image. The instructions can be found in the BMC BladeLogic User Guide.