"../foo.blah"
rara
wewe
wewe
rara
wewe
wewe
rara
"../bar.blah"

##</code><code>##

perl -pi -e 's/\"(\.\.\/.*?)\"/$1/g' blah.txt 

##</code><code>##

perl -pi -e 's/\"(\.\.\/foo\.blah)\"/$1/g' blah.txt

##</code><code>##

../foo.blah
rara
wewe
wewe
rara
wewe
wewe
rara
"../bar.blah"