Success

Here is how I got the fhz1300 working

Installed the supplied program in german

Went to device manager

Universal Serial Bus controlers
ELV FHZ 1300 PC
Right Click properties, in the advanced check VCP .. virtual comport

Reboot

On restart device manager
Ports (Com LPT)
should now show
ELV 1300 PC
right click update driver
Select Browse my computer
Navigate to FHZ1300
Drivers
On the supplied disk from elv

Click install next

Reboot

Device manager
Ports (com lpt)

ELV FHZ1300 PC should now show comport

in fhem.cfg
define FHZ FHZ COM6

comment out any other references to com etc

Oh one more thing
I installed ActivePerl
and ran the following command
ppm install Win32-SerialPort

Which cured the serailport errors.

Now All I have to do is to start to rename all the various auto added values in fhem.cfg to meaningfull info such as kitchen.

Hopefully this will help anybody else who has a go at FHEM