Licensing PortableApps with commercial license

I would like to know whether it would be possible to "license" the PortableApp launcher, so that it is not under GPL.

Here is the whole story.
Alfresco is an Enterprise Content Management software, and we have been shipping "LibreOffice Portable" as part of the installer, to perform some transformation on documents. Alfresco is dually licensed: LGPL and Commercial.
Lately, more and more of our customers are getting nervous about GPL components, and we have to argue with them to convince that it's OK. We would like to stop doing that.

Ideally, we would like to "retro-license" the PortableApp launcher under a commercial license, without changing our software. (We can't change past releases). That would allow us to reassure these customers, by simply changing the license on this component.

Would that be a possibility?

Thanks for your answer