I have commented a regex that works with the data that you have provided. The two values that you are looking for are placed in $2 and $3.

use strict;
use warnings;

my $a='
$text=~s#Find \#Text#Replace Text#;
$text=~s/Find \/Text/Replace Text/;
$text=~s{Find \}Text}{Replace Text};
';

if ($a =~ 
/        # start
\$text=~s    # remember to escape the $ to avoid interpolation
(.)        # capture the '#'
(.*?)        # match any non-newline character non-greedily
(?<!\\)        # make sure the '#' is not escaped in your data
\1        # the first unescaped '#'
(.*?)        # match any non-newline character non-greedily
\1;        # the second '#'
/x        # end
)


{
    # need value $findtext='Find \#Text';
    print "$2\n";
    # need value $repltext='Replace Text';    
    print "$3\n"
}
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