welcome hellohello1,
even if you can parse XML with regexes please do not do it..
I prefere to use XML::Twig but there are other options.
Here a chaotic list of reading:

http://www.effectiveperlprogramming.com/2011/07/rewrite-xml-with-xmltwig/ and http://www.effectiveperlprogramming.com/2010/03/process-xml-data-with-xmltwig/ and http://it-is-etc.blogspot.it/2012/07/perl-how-to-manipulate-xml-files-using.html and http://perlmeme.org/tutorials/parsing_xml.html speed comparison http://www.robinclarke.net/archives/xml-parsing-with-perl mirod schratchpad and Re: Another simple XML Twig question and http://www.xml.com/pub/a/2001/03/21/xmltwig.html ambrus's Do not reinvent the wheel: real-world example using XML::Twig and also http://perl-xml.sourceforge.net/faq/ and choroba about XML

HtH
L*