$str= "Some text1 : Data Some Text2";
$str=~/:\s+Data\s(.+)\z/;
$youwant=$1;             ##$1 is the captured (.+) part
print $youwant;

##</code><code>##

$str= "Some text1 : Data Some Text2";
$str=~s/.+?:\s+Data\s(.+)\z/$1/;
print $str;