Hi eu22106,
On windows, the "vxdisk diskinfo <harddisk# or PCTL>" command will provide the serial number in output for a specified disk. You can use a loop to go through all available harddisks until you find the serial number that you are looking for.
The "vxassist" command can be used to grow the volume using the "growby" option. This command would use the harddisk# or PCTL to select the exact disk to grow the volume to.
SFW also have the ability to automatically grow the volume and notify you when storage space limits have been reached. This option will automatically select the lun to grow the volume to. I know that this might not be exactly what you want since it sounds like you want to select exactly which luns the volume will be grown onto. But it might meet your needs with less scripting. Its just a thought.
Please let use know if this helps.
Thank you,
Wally