Having trouble with regex in mp3tag

Hey guys ... I am trying to do a replace ...

how can I search the following string for '_w' and find all the letters following that position until I hit a space ?

Here is a sample string "Suspense_1944-12-21_BrightonStrangler_wJohnLoder UPGRADE-2 SS"

I am trying to extract 'JohnLoder' in this example ...

I tried using :

_w(\S*)

and

(?<=_w)\S*

What am I doing wrong ? Thanks !!!! =)

The search string could be (without the inverted commas): "_w.* "

$regexp('Suspense_1944-12-21_BrightonStrangler_wJohnLoder UPGRADE-2 SS','^.*_w(.+?)\s.*$','$1')

==> JohnLoder
... or ...

$regexp('Suspense_1944-12-21_BrightonStrangler_wJohnLoder UPGRADE-2 SS','^.*_w(\S+).*$','$1')

==> JohnLoder

DD.20140313.0759.CET