I´ll try to explain the problem.
I tried to include ST data in a recipe and run into problems.
Please see the attached screenshot.
I tried to define the ST data in different ways to avoid getting an error and to be able to store and load the data in the recipe.
I used different ST records in the example (ST9:1, ST9:2, ....) just to make it easier to explain.
What I wanted to do is to save the complete string in the recipe.
In the first example (ST9:1.DATA[0]), as you already explained me before, this points to the first word (ST9:1.DATA[0] and ST9:1.DATA[1]). I miss all the other words in the record beyond the first one (from the 3rd character til lthe end of the string).
2nd example (ST9:2.DATA[0] with LENGTH=5). I tried here to get the first 10 characters (5 words) of ST9:2. As you can see, what I get are the first word of 5 different records (ST9:2, ST9:3, ST9:4, ST9:5 and ST9:6).
Third example, since in the 1st case I got just one word, I tried to define separately the 1st word (ST9:7.DATA[0]), the 2nd word (ST9:7.DATA[3]) and so on. I started with ST9:7="abcdef", I stored the recipe and when I loaded the recipe back, I just got the first word in ST9:7 ("ab"), I lost the others ("cdef" was lost).
The last example, I tried to referentiate the whole string using just ST9:8 and when I hit ENTER i get the error message shown.
So, I couldn´t find how to use ST data in recipes.