Thanks Lee, earlier I tried with your tutorial but I was mistaking somewhere or I was doing it in a wrong way.
One more trouble. I want to use strcat function for two lists.
e.g. list1 ("dwg" "dwgname" "dwgnumber" ...)
list2 ("x." "y." "z." ...)
output will be ("x.dwg" "y.dwgname" "z.dwgnumber" ...)