i don't know if HFSS could do this directly. but you could import the data file *.txt to other 3D software, like autocad ,then generate the file which could import into HFSS directly. Or. you could try vbs. you just record the script in HFSS, and see how the vbs works. change the data . run vbs .hope it can help you.
folk, you may just simple read a file in FWS format in the folder u save the project with notepad, then u can get the S11 parameters versus freq. and phases