Dynamic Frequency Analysis - test data as input

I have a question regarding importing test data as a driving function for Dynamic Frequency Analysis  (DFA) uding ascii format. I get the following error when I try to import the data. I can export the data in ascii format using diff delimitors (tab, space, comma, colon etc) but nothing seems to work. 

Any suggestions regarding Creo capabilities (I am using Creo 4) or if I need to change data format somehow ?

Also if someone has ran Dynamic Frequency or Time analysis in Creo with actual test data, are there any best practices to follow, reference material or lessons learnt ?

many thanks !