Track Automation With Nexus2

Hi All
I am quite a newby with both Cubase and Nexus. I am using Cubase 6.5 Artist Edition and Nexus2. The problem that i have is that when i want to automate parameters from Nexus in Cubase, the cubase parameters range from -127 to 127 with 0 as the middle value. In Cubase the range starts only at 0 so values below 0 seem to be not possible? I want to automate the cutoff level on some tracks. I am not sure whether it is an issue of Nexus or Cubase. Any suggestions welcome…
Thanks all!