Shell Programming and Scripting

 
>cat file
it would be easier to understand your requirement and assist you if you show it with sample file and desired output.
>sed -e 's/easier/& "HERE MY WORD"/' -e 's/sample/& "HERE MY WORD TOO"/' file
it would be easier "HERE MY WORD" to understand your requirement and assist you if you show it with sample "HERE MY WORD TOO" file and desired output.

newfile1=$(basename $curfile)
newfile2=$(cat $dir3/pagestotal |grep $newfile1 |cut -f1).art
untilrnd1=$(expr $RANDOM % 6 + 5)
iuntil=$(seq 0 $untilrnd1)
artwords=($(tail -n1 $dir3$newfile2))
mywordhere="HERE IS MY WORD"
:>articlegogo
for j in $iuntil; do
echo -n "${artwords[$j]} " >>articlegogo
done
echo -n "$mywordhere " >>articlegogo

untilrnd2=$(expr $untilrnd1 + 1)
untilrnd3=$(expr $untilrnd2 + $untilrnd1)
iuntil=$(seq $untilrnd2 $untilrnd3)
for j in $iuntil; do
echo -n "${artwords[$j]} " >>articlegogo
done
echo -n "$mywordhere " >>articlegogo

untilrnd4=$(expr $untilrnd3 + 1)
untilrnd5=$(expr $untilrnd4 + $untilrnd3)
iuntil=$(seq $untilrnd4 $untilrnd5)
for j in $iuntil; do
echo -n "${artwords[$j]} " >>articlegogo
done

$ cat file
hello mighty all there is a line of words and i need to take a random number of words from the beginning (20 words for example) 
then put my word then add other 10 words from the continue then add another my special word then add words till the end

$ wc -w file
50 file

$ awk 'BEGIN{srand()}{for(i=1;i<=20;i++) printf "%s ",$(int(rand()*50)+1);print ""}' file
my the 10 words put words need add of then 10 number till number need my take number my words 

$ awk 'BEGIN{srand()}{for(i=1;i<=20;i++) printf "%s ",$(int(rand()*50)+1);print ""}' file
my word then the words number line words take (20 my my take beginning hello is till words line add 

$ awk 'BEGIN{srand()}{for(i=1;i<=20;i++) printf "%s ",$(int(rand()*50)+1);print ""}' file
is add (20 beginning end hello the words the my words add then add words word a a of mighty