You should look at the ISHRemote powershell library. This library has the command 'Set-IshLovValue' which allows you to upload any LOV value into any specified 'LOV'.
So if you build up a powershell routine reading an input file which has the reference towards the LOV to which you want to upload the LOV Value together with the value, the command will add them.
Raf's reply will allow you to do this through PowerShell.
My only comment to you is: are you aware of the metadata binding extension that allows you link a custom KC metadata field with an external system to get live metadata. It's called the Metadata Binding. You can read more about it on :
Hello All, thanks for the response and if I want to use the ISHRemote is there a sample XML or excel file for the LOVvalue format, so that I can format out data accordingly.
Hi Suresh, I use the TriDK XML Setup to load LOV values, which allows me to set my own database keys instead of having the system assign random ones, comes in handy when multiple values need to be updated. docs.sdl.com/.../pub.xql