Do not post irrelevant questions to the end of a topic -- that's why you start new ones. I've split yours off.
You need to spend some time reading the COBOL manuals (link at the top of the page). If you do this reading, you will find that it is not possible in COBOL to access a file unless you know the record length. This is an absolute. Since you do not know the record length, what you want to do cannot be done. If you had a record length, you could read the entire record into a varaible and split it based on the space (using UNSTRING or reference modification or arrays).