.LNK is a shortcut file, not an NTFS soft symbolic link. The former can contain an editable Target field where you can add parameters, not the latter.
You can try creating a shortcut to portable_chrome.exe and in the Target field add index.html to it, so that it looks like
"Drive:\Path\to\portable_chrome.exe" index.html. While shortcuts cannot contain relative paths, launching them will cause them to auto-resolve so in this case whatever be the path portable_chrome.exe should be located and used since it exists in the same directory as the shortcut itself.
Alternately, you can create a one-liner Launch.bat batch file in the same directory with
portable_chrome.exe index.html in it.