Hi,
please have a look in the folder where Arbortext Editor is installed (usually something like C:\Program Files\PTC\Arbortext Editor). There you will find a subfolder "adapters" and within there "com.ptc.prowt.arbortext\bursting". In the bursting folder are a bunch of files ending with ".bcf" (assuming you have Arbortext version 6).
These are the so called burst configuration files (sometimes also refered to as burstspec). For DITA technical content you will need atidefaults.bcf (which defines the global default settings), bookmap.bcf, ditabase.bcf. Depending on what content types you are using you might also need map.bcf, keybase.bcf and ditaval.bcf.
To have Arbortext use these burstspecs you need to upload them to ACM (to a library or folder where all Arbortext users can read from). Use Arbortext Editor, connect to ACM, open the burstspecs you want to upload (beginning with "atidefault.bcf") and use "File->Save as server object" to store it. Make sure you enter the exact name of the burstspec file as ACM name (without the .bcf). Alternately you could set a Windows environment variable named "APTOBJCFG" and enter the complete path to the "bursting" folder mentioned above. You need to set the Environment variable before you start Arbortext Editor. I would recommend you make a copy of the bursting folder somewhere and point APTOBJCFG to that copied folder. You can then start modifying the burstspec files to your needs without touching the originals shipped with Arbortext.
Please refer to the Arbortext Help Center (Administration->Arbortext Editor, Styler, and Architect->Content Management Guide) for further information about the various options you can configure in the burst configuration files.
I hope that gives you the necessary information to get your DITA content into ACM with all the links correctly converted.
Kind regards
Sirko