Refer to Columns in other Data Table using Formula in Column Names

[#1]

I have a data table with column names having xy coordinates embedded in them. something like "delay [x,y]"

I'd like to use a list of [x,y] (attached) to construct the column names so I can refer to a specific column in that table.

When I tried to do subtractions referring to the column using dt:name() it errored out "Name arg must be quoted string". Any suggestions?  

list=xy<< get column names(String)
col="delay"||Substr(char(list[{1}]), 3,Length( char(list[{1}]))-4);
a=dt:name(char(col))[15]-dt:name(char(col))[25]

[#2 · Accepted solution]

Given the attached data table, the following JSL works.

dt=current data table();
list=dt<< get column names(String);
//col="delay"||Substr(char(list[1]), 3,Length( char(list[1]))-4);
col=list[1];
//a=dt:name(char(col))[15]-dt:name(char(col))[25]
a=column(dt,col)[15]-column(dt,col)[25];