Public Folder Migration from 2007/2010 to 2013 Cross Forest

Hi 

I am seeing if it possible to natively, through PowerShell migrate Public folders from 2007 and 2010 to 2013 on premise?

I cannot find any documentation from MS on this solution for Cross-Forest, only within the same organisations. URL https://technet.microsoft.com/en-GB/library/dn912663(v=exchg.150).aspx

if this is possible and if it is documented please could anybody share? Or is it only possible using 3rd party tools?

Thanks