But it's the whole concept of your snippet that is "the other way round"
You want to ONLY dd mylinux2.cfg over syslinux.cfg IF mylinux2.cfg exist (whether mylinux1.cfg exists or not is irrelevant) and, NO matter if the dd command is executed or not proceed with a chainloader /syslinux.bin command.
That would be:
find --set-root /syslinux.cfg if not exist /mylinux2.cfg echo File mylinux2.cfg is missing && echo Second line && echo Third line && pause if exist /mylinux2.cfg dd if=()/mylinux2.cfg of=()/syslinux.cfg chainloader /syslinux.binbut we can do "better" with:
find --set-root /syslinux.cfg if exist /mylinux2.cfg dd if=()/mylinux2.cfg of=()/syslinux.cfg || echo File mylinux2.cfg is missing && echo Second line && echo Third line && pause chainloader /syslinux.binRemember that the boot command is NOT needed in a menu.lst entry (as it is implied) while it is needed on command line.
Wonko