Find text with regex

Hi. I don’t understand the pattern in regex. What should I do to get: 12.411 m² from this string?:

<div class="s20 red">68.000.000 kr.</div>
<div class="remem">
<input type="checkbox" id="chkRemember_d6b706eaeb544dd6a319bc9d64db7f4e"/>
<label for="chkRemember_d6b706eaeb544dd6a319bc9d64db7f4e" class="gray bold s11 upper">Husk</label></div>
</div>
</div>
<div class="kf3 tip-white" title="Antal kvadratmeter grund (mæglerens registrering)"><span>Grund</span>12.411 m²</div>

This is my current code which I got from another answer.
string pattern = @“[1-9]{1}\d{0,2}.?(\d{1,3}.?)*\skr.”;
Regex regex = new Regex(pattern, RegexOptions.None);
Match m = regex.Match(data);

NODE EXPLANATION
--------------------------------------------------------------------------------
[1-9]{1} any character of: ‘1’ to ‘9’ (1 times)
--------------------------------------------------------------------------------
\d{0,2} digits (0-9) (between 0 and 2 times
(matching the most amount possible))
--------------------------------------------------------------------------------
.? any character except
(optional
(matching the most amount possible))
--------------------------------------------------------------------------------
( group and capture to \1 (0 or more times
(matching the most amount possible)):
--------------------------------------------------------------------------------
\d{1,3} digits (0-9) (between 1 and 3 times
(matching the most amount possible))
--------------------------------------------------------------------------------
.? any character except
(optional
(matching the most amount possible))
--------------------------------------------------------------------------------
)* end of \1 (NOTE: because you are using a
quantifier on this capture, only the LAST
repetition of the captured pattern will be
stored in \1)
--------------------------------------------------------------------------------
\s whitespace (
, \r, , \f, and " ")
--------------------------------------------------------------------------------
kr ‘kr’
--------------------------------------------------------------------------------
. any character except