Using oorexx 4.01 64bit, built from trunk 20 of june, on windows 7 64 bit
I tested this short rexx and HOSTEMU (execio) with read-only file as input and get Rc(20). Removing the read-only attribute on input file the program works
File="with read only attribute set"
address hostemu "execio * DISKR "file "(STEM infile. FINIS"
say "* Lines read" infile.0
do ix = 1 to infile.0
::requires 'hostemu' library