If you have the $set statement coded into your program, then you compile from the command line just as you would a program that is not XML enabled. However, if you do not have the $set statement coded into your program, or you would like to override all of the parameters specified in your $set statement, specify a command line as follows:
cob programname.cbl -C "{preprocess | p}(prexml)
[{out | o} (outname)]
[warn]
[outenc (input)]
[{preprocess | p} (ppname)]
endp"
where programname is the file prefix of the COBOL program you are compiling, and the other parameters are the same as those used with the $set statement.
For example:
cob foo.cbl -C "p(prexml) warn endp"