Topic: Dosbox can't see "Fireface 800 MIDI (GSIF low latency)"

I run "Texture" sequencer within Dosbox, and RME Fireface 800. (win7 Ultimate 64bit)
As I still use Gigastudio, the preferred driver for FF800 (29992) is "Fireface 800 MIDI (GSIF low latency)", however when I run "mixer /listmidi" in Dosbox all that appears is:-

0 "Microsoft GS Wavetable Synth"
1 "Fireface 800 midi"

No combination of the above works in the DB config file, and while I can get "Texture" to work through "LOOPmidi", etc the "Fireface 800 MIDI (GSIF low latency)" should be used as there is a latency difference.
Where would I find the file, and how do I get "Fireface 800 MIDI (GSIF low latency)" added to the list that shows up in "mixer /listmidi"? (Dosbox)
Any comment appreciated
cheers
Bryan H

Sager Laptop Intel quad 2.8
Win 7 Ult 64 bt
32 gb ram FF800, Reaper
Texture Dosbox 74