I don't know what you mean by "DataFlow"?? Data Flux??? Data Step program??
At any rate, you might search the forums, there have been previous postings about HL7 data. It depends on whether you have XML tags or just data that looks like what's contained in this previous posting (this is the previous post that I remembered): http://support.sas.com/forums/thread.jspa?messageID=15762㶒
If your HL7 data is in XML format, then you might be able to use the XML Libname Engine to read the data. It really depends on what the data looks like.