I can't remember the names of the different ones I've run across, but I know that (at least for some of the older versions of AutoCAD LT, i.e. 2000) there are add-ons that you can get, that provide lisp support for LT. Haven't heard if they support the latest release or not.
I'm sure somoene else here can point you in the right direction, since I can't remember the names.
Sorry.....