I've been working pretty steadily on a Strange Aeons RW input, and I feel like this might be a good place to put my 2 cents.
As AEIOU indicates, if you make a HL portfolio for an encounter, you can save the .por file and navigate and link to it in RW. This works for an encounter, say, against 10 goblins. Not likely to need to make changes. clicky click, it opens from RW into HL. Away you go. Downside: you're creating this potentially massive library of .por files that you have to either store in the cloud for access everywhere or copy them to your mobile devices, if you work in this way.
However... If you are working from a source, for instance an AP you have purchased from LWD, you have another option. You can simply click on the puzzle piece icon in RW from a HL Portfolio Snippet (identified as the triangle shaped logo for HL), and it will launch HL and you click through into your game system, and hit "OK".
You'll now have "Unnamed Hero" in a new portfolio.
You can navigate up to "Gamemaster" on the toolbar and select "Encounter Library" and find the specific encounter in the AP.
You confirm that the contents are what you want, click "Import" and it loads into the current Herolab view.
Remove the Unnamed Hero from the "Portfolio" toolbar option and then "Save Portfolio". It will save the portfolio IN RW.
Super important to remember that,. No .por file that you can see will be created, it simply exists IN RW as a clickable link. You can edit it, or whatever you want down the road, IN RW. But no changes you make will affect external files, or the Encounter Library entry. AEIOU called this out in his post (#2).
If you watch Daplunk's videos, you'll see his work with the Encounter Builder, which works fundamentally the same way, except you'll pick whatever creatures you want from your purchased options and then save portfolio and it just does it's thing, all without creating an external or "findable" .por file. Again, totally editable from RW, and no need to create some huge library of .por files for all occasions.
Thinking about what AEIOU has said, it may be a good idea to either open the party from the same .por file all the time, or only edit the file from a RW link. Keep in mind you cannot share the RW link with players who may want access.
I intend to keep the party .por file in a dropbox file and load from there, and then when I run the AP, just load the encounters from the RW links.