fScan Reference Manual, Chapter 2 (CmdLineOptions): set uservarb
-set varbname value
-set string varbname value
-set number varbname value
-set accept varbname promptstring
These SET commands create a user-defined variable called VARBNAME and set it to the specified VALUE. Variables can contain either numbers or text strings. A user-defined variable is created the first time it is set to a value. The variable is deleted if it is set to an empty value. Variables can be used in fScan commands as '$varbname'.
If VARBNAME is the first argument after SET and is not a name recognized by the SET command itself, the storage type will be inferred from the value being stored (number or string).
The STRING and NUMBER options force the variable to be stored as a text string or number, respectively.
The ACCEPT option prompts the user to enter the VALUE interactively.