The Mechanical GUI does not support passing strings into macros. The workaround would be to name the files such that they end with a number such as: file1,csv file2,csv file3,csv then pass the number in as arg1. The macro should be written to use file%arg1%,csv and there cannot be spaces in the path or filename. For example following macro will read data from file1.csv into table HGEN1. /INQUIRE,numlines,LINES,’D:ProjectFEA_1file%arg1%’,’csv’ rownum=numlines *dim,HGEN1,table,(rownum-1),(5-1) *tread,HGEN1,’D:ProjectFEA_1file%arg1%’,’csv’