I think you can import with VBA,
I have a different software (Prode Properties) which is much more integrated in Excel than Hysys being a process library, in Prode you can access data with Excel macros (for example you write =StrH(stream) in a cell and the library returns the enthalpy of a stream) or VBA, VBA requires a little work but it is flexible.
I would presume you can do the same with Hysys