Sorry, but could you please help me out with a sample script for reading from a list (say a particular row and column)?
Please try the following script:

Set V[line] 5
Set V[col1] 18
Set V[col2] 24
Title "String in line &V[line], from column &V[col1] to &V[col2]:
&V[_listline(&V[line])](&V[col1]-&V[col2])"

Explanation:

_listline(5) is line number 5 in the list. Its value is
"&V[_listline(5)]". With a variable line number &V[line] this becomes
"&V[_listline( &V[line])]". To address a substring, we use the notation
"&V[varname](from-to)".
So "&V[_listline(5)](18-24)" is the substring starting in column 18 and ending in column 24.
With symbolic columns
&V[col1] and &V[col2], we have the expression above.