Tom,
The PxPlus Excel object will look for Excel locally on the machine that instantiates the object (X_OBJ=new(*obj/excel). If you run the program on a workstation, that workstation will need to have Excel installed. If the program is run on the server - only the server should need to have Excel installed. However, the excel file created would also be on the server.
There may be ways around this if you do not use the PxPlus Excel Object.