IFS codepage question

I'm trying create a .RTF file via a stream file. I'm running into
problems that I suspect are caused by the codepage I'm using. For
starters I opened the stream file with a codepage of 819 and populated
it. When I opened the .RTF file all of RTF formatting syntax showed up.
Obviously that is because all of the data was translated as text. I then
tried codepages 427 and 850, but that didn't work either. 
Can anyone tell me if all I need to do is find the correct codepage, or
is there something else I should be looking into? I suppose it's also
possible that I'm not opening the stream file correctly. I'll post the
code that I have.

// Open 
RC2=open(TempStrmFile: O_CREAT+O_WRONLY+O_CODEPAGE: S_IWUSR: 850);

// Close file
Closef(RC2);

// Open again 
Open_Flag = O_WRONLY+O_TEXTDATA;
RC2 = Open(TempStrmFile:Open_Flag);

Thanks in advance. 
P.S. I'm not using database files so CPYTOPCD isn't an alternative as
far as I know.