Complex CSV parsing with Linux commands

I haven't tested this; try it and let me know if it works.

awk -F';' '
    $3 == "HC" {
        if (NR > 1) {
            print sum
            sum = 0 }
        next }
    { sum += $3 }
    END { print sum }'

awk solution:

$ awk -F';' '$3=="HC" && p{
    print sum          # print current total
    sum=p=0            # reinitialize sum and p
    next
 }
 $3!="HC"{
    sum=sum+($3+0)     # make sure $3 is converted to integer. sum it up.
    p=1                # set p to 1               
 }                     # print last sum
 END{print sum}' input.txt

output:

14
28
51
0
37
10

one-liner:

$ awk -F";" '$3=="HC" && p{print sum;sum=p=0;next} $3!="HC"{sum=sum+($3+0);p=1} END{print sum}' input.txt

awk -F';' '/^H.*/{if(f)print s;s=0;f=$3=="HC"}f{s+=$3}END{if(f)print s}' infile

For given inputs:

$ cat infile
HA;HB;HC;HD;HE
a1;b1;14;d;e
HA;HB;HC;HD;HE
a2;b2;28;d;e
HA;HB;HC;HD;HE
a31;b31;44;d;e
a32;b32;07;d;e
HA;HB;HC;HD;HE
a4;b4;0;d;e
HA;HB;HC;HD;HE
a51;b51;32;d;e
a52;b52;0;d;e
a53;b53;5;d;e
HA;HB;HC;HD;HE
a6;b6;10;d;e

$ awk -F';' '/^H.*/{if(f)print s; s=0; f=$3=="HC"}f{s+=$3}END{if(f)print s}' infile
14
28
51
0
37
10

It takes little more care for example:

$ cat infile2
HA;HB;HC;HD;HE
a1;b1;14;d;e
HA;HB;HC;HD;HE
a2;b2;28;d;e
HA;HB;HC;HD;HE
a31;b31;44;d;e
a32;b32;07;d;e
HA;HB;HC;HD;HE
a4;b4;0;d;e
HA;HB;HD;HD;HE         <---- Say if HC does not found
a51;b51;32;d;e
a52;b52;0;d;e
a53;b53;5;d;e
HA;HB;HC;HD;HE
a6;b6;10;d;e

# find only HC in 3rd column
$ awk -F';' '/^H.*/{if(f)print s; s=0; f=$3=="HC"}f{s+=$3}END{if(f)print s}' infile2
14
28
51
0
10

# Find HD in 3rd column
$ awk -F';' '/^H.*/{if(f)print s; s=0; f=$3=="HD"}f{s+=$3}END{if(f)print s}' infile2
37

eval "true || $(cat data.csv|cut -d ";" -f3 |sed -e s/"HC"/"0; expr 0"/g |tr '\n' '@'|sed -e s/"@@"/""/g|sed -e s/"@"/" + "/g)"

Explanation:

1. Get contents of the file using cat
2. Take only the third column using cut delimiter of ;
3. Replace HC lines with 0; expr 0 values to start building eval-worthy bash expressions to eventually yield expr 0 + 14;
4. Replace \n newlines temporarily with @ to circumvent possible BSD sed limitations
5. Replace double @@ with single @ to avoid blank lines turning into spaces and causing expr to bomb out.
6. Replace @ with + to add the numbers together.
7. Execute the command, but with a true || 0; expr ... to avoid a guaranteed syntax error on the first line.

Which creates this:

true || 0; expr 0 + 14 + 0; expr 0 + 28 + 0; expr 0 + 44 + 07 + 0; expr 0 + 0 + 0; expr 0 + 32 + 0 + 5 + 0; expr 0 + 10

The output looks like this:

14
28
51
0
37
10

This was tested on Bash 3.2 and MacOS El Capitan.

Could you please try following and let me know if this helps you.

awk -F";" '
/^H/ && $3!="HC"{
  flag="";
  next
}
/^H/ && $3=="HC"{
  if(NR>1){
    printf("%d\n",sum)
};
  sum=0;
  flag=1;
  next
}
flag{
  sum+=$3
}
END{
  printf("%d\n",sum)
}
'   Input_file

Output will be as follows.

14
28
51
0
37
10

$ awk -F';' '$3=="HC"{if (NR>1) print s; s=0; next} {s+=$3} END{print s}' file
14
28
51
0
37
10