Time Date formatting question...

Back in the good old days of PHP and even now.. you could set the date and time up any way you liked by just adding any separator you liked and positioning the variables in any sort of way...
But I cannot find the same here in autoit unless I just don't understand what I am reading..

For example my date time comes out:
2/23/2013 and time is ok like 13:51:34 for 24 hour time...
but here is what i need:
2013-23-02 13:51:34 but to get this I am doing a lot of jacking around... am I making this too hard?

$mytime = _NowDate() & " " & _NowTime(5)

2/23/2013 13:51:34 Need 2013-23-02 13:51:34

Just changing the : to a dash and changing the / to a dash..
But isn't there a format that gives the above without all the work?

$fname = "data\" & $key_phrase & "-" & $mytime & ".htm"
$fname = StringRegExpReplace($fname, "/", "-")
$fname = StringRegExpReplace($fname, " ", "-")
$fname = StringRegExpReplace($fname, ":", "-")