How can I change last 4 digits of co_end_variable to finyear ?

For the data below, for example, 01jan2001-> 01jan1998 and 28oct2003 -> 28oct2002



. dataex co_end_date finyear

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Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input str9 co_end_date str4 finyear
"01jan2001" "1998"
"28oct2003" "2002"
"31dec1998" "1993"
"01nov2001" "1999"
"01mar2001" "1993"
"28dec2003" "2002"
"31dec1993" "1993"
"01mar1998" "1994"
"01jan2023" "2000"
"01nov1993" "1992"
"01dec2000" "2000"
"01oct1994" "1992"
"23apr2001" "1998"
"31oct1995" "1994"
"31dec1994" "1994"
"01jan2023" "1996"
"01apr1994" "1993"
"27jul1998" "1993"
"01jul2001" "2000"
"01aug1994" "1994"
"12may1996" "1993"
"01apr2000" "1992"
"25oct2002" "1998"
"31dec1994" "1994"
"31dec1994" "1994"
"01jul2002" "1996"
"06may1999" "1999"
"31dec1993" "1993"
"27jan2004" "2004"
"15mar1996" "1993"
"03may1995" "1993"
"31dec1994" "1992"
"31mar1993" "1993"
"28apr1993" "1993"
"01feb1993" "1993"
"01apr1997" "1994"
"01may2018" "1995"
"01may2001" "2001"
"14mar2005" "1998"
"01oct1995" "1995"
"01jan2023" "1992"
"01jan2023" "1992"
"08jun2020" "2019"
"31oct1997" "1994"
"01jan1998" "1995"
"31may1994" "1993"
"31dec2000" "1992"
"10may2000" "1997"
"01jan2023" "1992"
"31dec1998" "1998"
"31aug1996" "1994"
"01dec2003" "2001"
"02nov1996" "1996"
"30jun2002" "1999"
"01aug2008" "2001"
"15jan2009" "2000"
"14oct1993" "1992"
"01apr2003" "2000"
"17apr1997" "1995"
"01jan2023" "1994"
"01jan2023" "1992"
"30apr1994" "1992"
"01jan2023" "1992"
"01sep2002" "1993"
"15jul2003" "2001"
"01may1998" "1997"
"31dec2006" "2006"
"01apr1999" "1997"
"01oct1996" "1996"
"02nov1995" "1995"
"01feb1998" "1994"
"01jan2023" "1992"
"30jun1995" "1992"
"01jan2023" "1995"
"01aug2006" "2002"
"17feb2009" "1997"
"06sep2011" "2010"
"01aug1996" "1993"
"18mar1997" "1997"
"01may2000" "1997"
"26jun1998" "1997"
"06may1999" "1996"
"01jan1997" "1993"
"17jun1994" "1993"
"21dec1999" "1999"
"01aug1994" "1993"
"01jan2023" "1995"
"27jul1995" "1995"
"07feb1998" "1992"
"31dec1995" "1995"
"30apr1995" "1992"
"01oct1993" "1992"
"01jan2023" "1996"
"01jan2023" "1998"
"28feb2006" "2004"
"28feb1997" "1995"
"01jan2000" "1997"
"31dec1997" "1997"
"31dec2008" "2004"
"08jan2008" "2003"
end
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