None, unless you want to count 'diesel' as a programming language, (not many people do. There are no API's available in LT that is one of the reasons it is so much more affordable. If you want any form of automation in LT then you would need to look at using an external program to create scripts, but there can be no interaction between a script and a .dwg file except for the script file telling LT to draw objects basically.
Seriously if you want automation then you have to have the full version.