I will first point you to the next resources: <a href="http://zone.ni.com/devzone/cda/tut/p/id/3005" target="_blank">An Introduction to NI-DAQmx
Tools for Data Acquisition with The Mathworks, Inc. MATLABŽ Software</a>.
Things like anti-alias filtering in DAQmx are must of the time changed by a
property node, in LabVIEW and a function when coding in C, for example in the C
reference help there are functions for: Get/Set/Reset
AI_EnhancedAliasRejectionEnable
How are you currently interfacing with DAQmx? Are you using a
toolkit or are you loading the driver library (DAQmx dll)?
If you are making calls directly to the driver you have to
options, you can either configure your task in MAX (Measurment automation
explorer), and in the task window you will have an option for low pass filter
enable or you can directly call the function: ?Get/Set/Reset
AI_EnhancedAliasRejectionEnable?.
Let me know if it helps
Screen shoots speak more than a million words