You could try manually creating a new file and saving it, say as LENS.ZMX, in the default directory.  Then, in your ZPL code use LOADLENS to load it in place of the existing model.

LOADLENS "LENS.ZMX", 0, 1
UPDATE ALL

Hi Mike,

As we all know, ZPL is the original built-in scripting language.  It’s reasonably powerful and fairly easy to use.  In the past, it was also possible to programmatically manipulate models using a third-party language that supported DDE extensions (like C or Matlab).  However, DDE extensions are now depricated, having been replaced by ZOS-API which is extremely versatile, providing methods for implementing almost any operation that can be done manually inside the GUI.   

ZOS-API is based on object-oriented programing and allows scripts to be written in a third-party language.  So, if you want to learn ZOS-API, the first step is to pick your language of choice (options include: C++, C#, Matlab, Python or Mathematica).  There are several example scripts provided in the ZOS-API Syntax Help documentation.  For your case, to get started, you can take a look at Example 01 (New File and QuickFoucs).

So, in a nutshell, ZPL and ZOS-API are two separate methods for scripting.  Not sure why you would want to try and mix them.  If you have a lot of ZPL macros already written, and need to tweak them, I think it’s probably best to look for pure ZPL solutions (as opposed to trying to mix ZPL with ZOS-API, which I’ve never seen done before, but perhaps it is possible). 

However, ZOS-API is by far the more powerful of the two scripting approaches (allowing a user to do things that simply aren’t possible with ZPL), but be forewarned that the learning curve for ZOS-API is a bit steep.  I had to work through several examples on many separate occasions to really get the hang of it.  I primarily use Matlab for this purpose, and find that OpticStudio under Matlab control (via the “Interactive Extension” mode of operation) can be quite useful.

Regards,

Jeff