1) Save your transaction history from your Internet banking as showed on the following picture:

Exporting link

2) Run following script on saved file:

#!/usr/bin/perl

use utf8;

if ($#ARGV != 1 ) {
    print "usage: csob.pl inputfile outputfile\n";
    exit;
}

open INPUT, "<:encoding(cp1250)", $ARGV[0];
open OUTPUT, ">:encoding(utf8)", $ARGV[1];
print OUTPUT "\n";

while(<INPUT>) {
    if (/:/) {
        ($key, $value) = split(/:\s*/, $_, 2);
        $value =~ s/\s*\n$//;
        if ($key eq "datum zaúčtování") {
            ($day, $month, $year) = split (/\./, $value);
            $value = "$year/$month/$day";
        }
        $values{$key} = $value;
    } else {
        if ($values{"částka"}) {
            print OUTPUT ";";                                       #1="transactionId"
            print OUTPUT "0300;";                                   #2="localBankCode"
            print OUTPUT ";";                                       #3="localAccountNumber"
            print OUTPUT ";";                                       #4="remoteBankCode"
            print OUTPUT ";";                                       #5="remoteAccountNumber"
            print OUTPUT '"'.$values{"datum zaúčtování"}.'";';      #6="date"
            print OUTPUT '"'.$values{"datum zaúčtování"}.'";';      #7="valutadate"
            print OUTPUT '"'.$values{"částka"}.'";';                #8="value/value"
            print OUTPUT '"'.$values{"měna"}.'";';                  #9="value/currency"
            print OUTPUT ";";                                       #10="localName"
            print OUTPUT '"'.$values{"název protiúčtu"}.'";';       #11="remoteName[0]"
            print OUTPUT ";";                                       #12="remoteName[1]"
            print OUTPUT '"'.$values{"označení operace"}.'";';      #13="purpose[0]"
            print OUTPUT '"'.$values{"poznámka"}.'";';              #14="purpose[1]"
            print OUTPUT '"'.$values{"konstantní symbol"}.'";';     #15="purpose[2]"
            print OUTPUT '"'.$values{"variabilní symbol"}.'";';     #16="purpose[3]"
            print OUTPUT '"'.$values{"specifický symbol"}.'";';     #17="purpose[4]"
            print OUTPUT ";";                                       #18="purpose[5]"
            print OUTPUT ";";                                       #19="purpose[6]"
            print OUTPUT ";";                                       #20="purpose[7]"
            print OUTPUT ";";                                       #21="purpose[8]"
            print OUTPUT ";";                                       #22="purpose[9]"
            print OUTPUT ";";                                       #23="purpose[10]"
            print OUTPUT ";";                                       #24="purpose[11]"
            print OUTPUT ";";                                       #25="category[0]"
            print OUTPUT ";";                                       #26="category[1]"
            print OUTPUT ";";                                       #27="category[2]"
            print OUTPUT ";";                                       #28="category[3]"
            print OUTPUT ";";                                       #29="category[4]"
            print OUTPUT ";";                                       #30="category[5]"
            print OUTPUT ";";                                       #31="category[6]"
            print OUTPUT "";                                        #32="category[7]"
            print OUTPUT "\n";
        }
        %values = ();
    }
}

close INPUT;
close OUTPUT;

3) Import newly created file into KMyMoney using default CSV importer.