$ cat datefile.csv
column1,column2,column3,column4,column5,column6, column7, Column8, Column9, Column10
"12","B000QRIGJ4","4432","string with quotes, and with a comma, and colon: in between","4432","author1, name","890","88","11-OCT-11","12"
"4432","B000QRIGJ4","890","another, string with quotes, and with more than, two commas: in between","455","author2, name","12","455","12-OCT-11","55"
"11","B000QRIGJ4","77","string with, commas and (paranthesis) and : colans, in between","12","author3, name","333","22","13-OCT-11","232"

$ awk -f csv2.awk datefile.csv
column1,column2,column3,column4,column5,column6, column7, Column8,"00/00/2000", Column10
"12","B000QRIGJ4","4432","string with quotes, and with a comma, and colon: in between","4432","author1, name","890","88","10/11/2011","12"
"4432","B000QRIGJ4","890","another, string with quotes, and with more than, two commas: in between","455","author2, name","12","455","10/12/2011","55"
"11","B000QRIGJ4","77","string with, commas and (paranthesis) and : colans, in between","12","author3, name","333","22","10/13/2011","232"

$ cat csv2.awk
BEGIN {
        if (NUMCOLS == "") NUMCOLS=32
        if (DELIM == "") DELIM = "\t"
        if (REPL == "") REPL = "~"
         split("JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC", month, " ")
        for (i=1; i<=12; i++) mdigit[month[i]]=i
}
{
        gsub(DELIM, REPL)
        $0 = gensub(/([^,])\"\"/, "\\1'", "g")
        out = ""
        n = length($0)
        for (i = 1;  i <= n;  i++) {
                if ((ch = substr($0, i, 1)) == "\"") {
                        inString = (inString) ? 0 : 1
                }
                out = out ((ch == "," && ! inString) ? DELIM : ch)
        }
        nfields=split(out,outfields,DELIM);

         # Do stuff with date
        m=substr(outfields[9],5,3)
        outfields[9] = sprintf("\"%02d/%02d/"20"%02d\"",mdigit[m],substr(outfields[9],2,2),substr(outfields[9],9,20))

        for (i=1;(i<=nfields)&&(i<=NUMCOLS);i++) {
                if (i > 1) {
                        printf (",");
                }
                printf ("%s", outfields[i]);
        }
        printf ("\n");
}