If you need to do some basic batch scripting sooner or later you will have to insert input from command line to a variable. In Linux this is done with read command, i.e.:
$ echo -n "Type a password for admin:";
$ read line;
$ echo $line;
So here is how to do the same if you need it for a Windows Batch (.BAT) file
C:\Users\> Set /p string='What do you want to ask?:'
'What do you want to ask?:'
This will define the string variable, to later print out the variable use:
> echo %string%
variable input output