Maybe this small B.A.S.I.C. snippet would explain it.
{L_CODE}:
DIM data$(4): REM Pretend this is a file and not stored in memory, 4 locations to hold 4 string items.
REM declare empty variables as integer
a = 0
b = 0
c = 0
d = 0
REM Assign data to each location simulating the NC in LSL.
data$(1) = "10"
data$(2) = "20"
data$(3) = "30"
data$(4) = "40"
REM Now read each location and assign a different variable to it's data, but being that the locations contain string data, a conversion is required to turn them into integer.
a = val(c$(1)): REM using an if condition here in LSL would check to see if a = 0 and if it does then assign a new variable as bool FALSE otherwise if a = 1 then assign that new variable to bool TRUE
b = val(c$(2))
c = val(c$(3))
d = val(c$(4))
Hopefully this helps,,,, being that I'm and old school BASIC programmer, this is the only way I can explain it

What I wanted was to have an NC with 4 items in 4 lines
{L_CODE}:
0
20
30
40
Then a script would read that NC 1 line at a time, and each line's data would be assigned to different variables.
EG
Being that NC lines start at 0 and NC data is text.
Line 0 = 0, a bool expression, thus assign a string variable to contain it's data, then check to see if that data is 0 or 1, and assign a new variable as an integer bool TRUE or FALSE
Line 1 = 20 assign a different variable but convert it from string to integer
Line 2 = 30 do the same
Line 3 = 40 do the same
Similar to this explanation:-
First check how many lines in the NC and use that as the EOF
Read NC line 0, assign a string variable then check to see if it's a 0 or 1 and if 0 then convert to integer and assign a different variable to FALSE, but if 1 then convert it to integer and assign that same new variable to TRUE
Read NC line 1, convert it's data from string to integer and assign another variable to it's data.
Read NC Line 2, the same
Read NC Line 3, the same
Resulting in 4 integer variables, each containing 1 line of the NC's data.
What shouldn't happen is the entire NC being read as one lump shot, and not using a loop of any kind,,, each line of the NC should be read individually, with each line's data being contained in 4 separate variables.