Technically this can be done, We do the opposite and have a similar type of setup for our USB boot devices where as it defaults to wiping systems but has the option to still launch LDPROVISION. You could modify the boot.wim file used during LDMS PXE Boot, include your batch file and / or edit startnet.cmd and insert your batch command before the LDPROVISION section. You might modify your batch to include launching the LDPROVISION.EXE section. Always make a backup copy before modifying the boot.wim file in case of unexpected results.
Thanks for your reply . I ended up mounting the boot.wim LANDesk provided and just editing the startnet.cmd file to point to my menu. I had to tweak some additional file paths and such, but it's working great now. I appreciate the help!