Perl Script Help first day of the given weekn in a year

[cemokam]

Hello Forum,

I have text data  for to manipulation. I get string like "201319" so "19" refers the week of the year 2013.

I wan to get the first day of this week (19).

Actually;here is my source.txt;

"SA4";"00000000000003";"0160";"001";"36.25402.6480";0000;2;;"Immediate";"Weekly";130519;"0";0;0;0;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Released";"Weekly";130203;"0";0;30;30;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;19;;"Planned";"Weekly";;"0";0;30;30;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;20;;"Planned";"Weekly";;"0";0;0;0;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Planned";"Monthly";130501;"0";0;60;60;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Planned";"Monthly";130601;"0";0;90;90;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Planned";"Monthly";130701;"0";0;120;120;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Planned";"Monthly";130801;"0";0;180;180;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Planned";"Monthly";130901;"0";0;60;60;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;0;;"Planned";"Monthly";131001;"0";0;85;85;;;"SA4_END";
"SA6";"00000000000003";"0160";"001";"36.25402.6480";"09840190091";"";30;;;;;;;;;"SA6_END";

I have to go to the strings ;

"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;19;;"Planned";"Weekly";;"0";0;30;30;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;20;;"Planned";"Weekly";;"0";0;0;0;;;"SA4_END";

Then get the final date as yymmdd from 19th week of 2013----->130506 (because the 19th week of 2013 is May and

the first day of the week is 06)

20th week of 2013----->130513---->(because the 20th week of 2013 is May and the first day date of week is 13th of May

Then I have to add these strings as below then save my source.txt

"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;19;130506;"Planned";"Weekly";;"0";0;30;30;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;20;130513;"Planned";"Weekly";;"0";0;0;0;;;"SA4_END";

[cemokam]

I have to change these records as ;then save my source.txt

"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;19;130506;"Planned";"Weekly";;"0";0;30;30;;;"SA4_END";
"SA4";"00000000000003";"0160";"001";"36.25402.6480";2013;20;130513;"Planned";"Weekly";;"0";0;0;0;;;"SA4_END";