An XML file can be read from a MEMPTR as the following code fragment demonstrates:

DEFINE VARIABLE memfile AS MEMPTR NO-UNDO.
. . . 
FILE-INFO:FILE-NAME = "meminp.xml".
SET-SIZE(memfile) = FILE-INFO:FILE-SIZE.

INPUT FROM "meminp.xml" BINARY NO-CONVERT.
IMPORT memfile.
INPUT CLOSE.
hDoc:LOAD("memptr",memfile,FALSE).
. . .