DatToXml Filter (Script-based)
For complete control over the data conversion process, there is no better method than using a script-based solution. Fortunately, you do not need to start from scratch. A DatToXml.wjs is included with DocOrigin. It provides a strong basis for converting .DAT to .XML. In fact, it can often be used as is.
However, if that is the case then please use ConvertDatToXml instead.
But you may want to code in some special processing for your situation. In that case, take a copy of the supplied DatToXml.wjs and modify it, likely only slightly, to get the result you want. There is additional documentation in the comments at the bottom of the supplied script.
BTW, if you believe the processing option you need is or would be common to your JetForm Central brethren, please do let us know so we can consider it as an additional feature of the ConvertDatToXml default filter.