Beginner's questions

[Pierre RUEL]

Hello,
I'm just beginning with Lilypond (after some years of practice with 
other notation softwares). In fact I've produced some PC programmed 
music and wan't to use Lilypond as an interface between VBA produced 
.txt code and music.
I have a huge .ly file of more than 400 A4 pages and the .log window 
lists a relatively small number of various errors but indefinitely 
repeated. And I have some difficulty to understand the .log 
observations. For instance, the .log stops at (sorry I'm of french 
mother thongue and use "italiano.ly"):
<do''2 reb''2>
and the analysis of the soft says:
"syntax error, unexpected STRING, expecting > or DRUM_PITCH or 
MUSIC_FUNCTION or NOTENAME_PITCH"
<
 do''2 reb''2>
Could anybody explain  what is that "guilty" STRING ?

I don't understand either why a > is expected here.

Additional precision: I've a "relative c''" at the beginning and I 
shouldn't write '' after the notes (I believe). In fact I get the same 
errors with or without the '' after the notes themselves.
Thant you for any explanation.
Friendly regards
Pierre