The block of code looks similar to what I receive using the REST Client utility. I also wondered if QTP would allow me to capture long blocks of XML. It did. I got tens of thounds of characters to be captured using code such as:
On huge strings(probably 10X more than in your example) there was a limitation from Excel, but I got around that by getting one of the properties of the REST Client object.
' Put the value from the global data sheet into a variable.
RBP = DataTable("RBP",dtGlobalSheet)