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"
cobol programname.cbl {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"
cobol foo.cbl p(prexml) warn o(foo.pp) endp