Gnuplot: Plotting from *txt files from different directories by reading column header

[Mohammed Atta]

My folder structure looks kind of like this

$ tree
.
├── Original_folder
│   └── cat.txt
├── folderCD
│   └── cat.txt
├── folderGK
│   └── cat.txt
├── folderFE
    └── cat.txt

Each cat.txt file has 5 line before starting the column header.
Sample cat.txt file is like this

Version LRv1.10.0
Build date 2017-12-06
MOL-calc
PRESSURE
!                       
      Time[s]     InletT[K]   InletP[Pa]   O2_GasOut     C_GasOut
       100         0.000885   1000000       0.0007       0.2111
and so on....

I want to plot first column along with the column which have column header with a keyword "_GasOut". (There are unknown number of header with this keywords, For each column I would like to have a separate graph). Additionally, the graphical results of Original_folder should be plotted in the same graph for all the plots from folderCD, folderGK, folderFE...... and so on.

Corresponding graph should be saved in the corresponding folders with a title same as column header. In each graph there should be two legend one is "original_folder" and another is "folderCD/folderGK/......"

I got all the output plot commands for Original_folder in one txt file and plot commands for all the other folders into another txt file. After that I am not finding a way to go ahead..

Here is the code

#!/bin/bash

gawk -F $'\t' '                                     # Using TABs as field separators
   /_GasOut/{                                       # On lines containing "_GasOut"
      for(f=1;f<=NF;f++){                           # ... iterate over all fields on line
         this=$f                                    # ... picking them up
         if(index(this,"_GasOut"))wanted[f]=1       # ... and noting which ones we want to print
      }
   }
   ENDFILE{                                         # As we reaach end of each file
      for(f in wanted){                             # ... iterate over wanted fields
         if(length(cmds)) cmds = cmds ",\n"         # ... adding commas and newlines if needed
         cmds = cmds "\"" FILENAME "\" using 1:" f  # ... and adding the "using" statement
      }
      delete wanted                                 # Forget list of wanted fields for next file
   }
   END{                                             # At very end of last file
      print cmds                                    # ... print accumulated gnuplot cmds
   }

   ' folder*/cat.txt

The output txt file look like this
```
(Original_folder)
"Original_folder/cat.txt" using 1:22,
"Original_folder/cat.txt" using 1:23,
"Original_folder/cat.txt" using 1:24,
"Original_folder/cat.txt" using 1:25,
"Original_folder/cat.txt" using 1:26,
"Original_folder/cat.txt" using 1:27,
"Original_folder/cat.txt" using 1:28,

If the same code is used again for other folders.. the output is like this...

(Other folders)
"folderCD/cat.txt" using 1:22,
"folderCD/cat.txt" using 1:23,
"folderCD/cat.txt" using 1:24,
"folderCD/cat.txt" using 1:25,
"folderCD/cat.txt" using 1:26,
"folderCD/cat.txt" using 1:27,
"folderCD/cat.txt" using 1:28,
"folderGK/cat.txt" using 1:22,
"folderGK/cat.txt" using 1:23,
"folderGK/cat.txt" using 1:24,
"folderGK/cat.txt" using 1:25,
"folderGK/cat.txt" using 1:26,
"folderGK/cat.txt" using 1:27,
"folderGK/cat.txt" using 1:28

So i have all the command ready for gnuplot "plot" command, I just don't know how to arrange them to get a plot.

For example
for column 22 it is like 

gnuplot>plot "Original_folder/cat.txt" using 1:22, \
"folderCD/cat.txt" using 1:22
```
How can I do this for all other cases ? And how to make the column header as title?
N.B: folder numbers are not fixed.
I added one of the cat.txt file for reference. https://1drv.ms/t/s!Aoomvi55MLAQh1wMmpnPGnliFmgg