sort lines in file based on specific location character
===

I want to sort a file based on specific character in a .txt file.

**This is a file given to me:**

    12345678901234567890123456789012345
    header     1stfoo   DDMMYYYY 2ndfoo
    sltele     Hoodie   24051988 d12Hdq
    sltele     Hoodie   07051987 d30Hdq
    sltele     Hoodie   07082011 d08Hdq
    sltele     Hoodie   09081961 d04Hdq
    sltele     Hoodie   20041962 d14Hdq
    sltele     Hoodie   20032000 d01Hdq
    sltele     Hoodie   13062002 d05Hdq

As you can see there is a column contains date with DDMMYYY format. If I sort it with  `sort -n -k 3,3 thisfile.txt > sortedfile.txt` i got this result:

    sltele     Hoodie   07051987 d30Hdq
    sltele     Hoodie   07082011 d08Hdq
    sltele     Hoodie   09081961 d04Hdq
    sltele     Hoodie   13062002 d05Hdq
    sltele     Hoodie   20032000 d01Hdq
    sltele     Hoodie   20041962 d14Hdq
    sltele     Hoodie   24051988 d12Hdq
    

but, I want the result like this:

    sltele     Hoodie   09081961 d04Hdq
    sltele     Hoodie   20041962 d14Hdq
    sltele     Hoodie   07051987 d30Hdq
    sltele     Hoodie   24051988 d12Hdq
    sltele     Hoodie   20032000 d01Hdq
    sltele     Hoodie   13062002 d05Hdq
    sltele     Hoodie   07082011 d08Hdq
    
As a valid sortedfile.txt based on DDMMYYYY date format.

can somebady help me?

thanks in advance

