|What do you mean by "opening the DOS program"?|
Maybe you can use debug or a hexadecimal editor to view its internal structure, but you face a pure binary file as any executable is. To get it disassembled is not an easy job and more you have to know what language was used to code it.
At first sight based on what you post I suppose it is trying to access a port, operation forbidden under NT kernel systems as XP. A workaround may be to run the application inside a virtual maxhine like Virtual PC 2004, but more info is needed and result is not guaranted.