For export in DEWESoft X3 64bit we found a solution that will work without an installation of full matlab 64bit.
To do this please install the Matlab Runtime Environment that is available on the MathWorks website.
This is freely available to anyone.
We tested with version R2018a (9.4) 64 bit.
To make it work you also need to update Dewesoft to the latest SP3 version.
To update the 64bit version just replace the binaries in the DEWESoft\X3\Bin64 with the one supplied in the .zip file.