[Info-vax] SYS$CREPRC output to file but its overriding and not appending

[HCorte]

Running a script/command procedure using the CREPRC with the image LOGINOUT the  OUTPUT_PATH is a logical name as is the SCRIPT_PATH and  ERROR_PATH.
The logical name OUTPUT_PATH point to a file.LOG;1 specifying the version 1 to not generate multiple files since its running every 5 seconds the script/SYS$CREPRC.       

ISTAT = SYS$CREPRC(pidadr,"SYS$SYSTEM:LOGINOUT.EXE",
     *    SCRIPT_PATH,                             !input
     *    OUTPUT_PATH,                             !output log
     *    ERROR_PATH,                              !error log
     *    ,,"MILLCON",,,,)                         !process name   

But instead of appending the new log information to the preexisting one its simply overriding.

In documentation 
VSI_PROGRAM_CONCEPTS_VOL_I.pdf

page 28 refers to 
"In a program that creates a subprocess, you can cause the subprocess to share the input, output, or error device of the creating process"

that's not the case that interest me but later on talks about 

"Use the Assign I/O Channel (SYS$ASSIGN) system service to assign an I/O channel to the device for input/output operations."

 so my question is SYS$ASSIGN the way to go to make the new log info append to the existing one on file.LOG;1? a bit lost at this point ...

Thanks for any help.