I have attempted to port the Linux DHCP client to VMS. The port is still somewhat incomplete and lacks many features of the original program. However, it can obtain a dynamic IP address for your VMS box. Be sure to read the README file.
You will need the Multinet TCP/IP stack from Process Software..
Source package: (approximately 0.112 MB) dhcpc20000107.zip
Decompression tools: The source packge is in a zip file. Use unzip to extract the source files.