Attached is an example of what I am asking.
There are two options. You can have Workflow generate a URL to the document in either WebLink, or WebAccess. You'd then need to use the Enterprise Integration tools in Workflow to insert that URL into the field in FireRMS that stores the "Linked to" field data.
The second option is to use the Laserfiche Client, but it's a little more involved. You'd have to use the Script activity to output an LFE file to a file share somewhere. Then you could use Workflow to inject a pointer to that file into the FireRMS database. You'd need a developer, but it's fairly trivial to generate the LFE file in memory and write it to disk.
Let me know if you'd like a little more detail on either of those solutions.
If you are not doing a ton of these then another option is to drag and drop a shortcut into a network folder which would create a Laserfiche Shortcut File (LFE) in which you would then browse to it to select it as a link. Those with the Laserfiche Client would then click on that link which would open the document/folder directly.
The link in your program would show for example, "\\networkshare\mylaserficheshortcut.lfe"