THANKS!
I solved this problem just a few minutes after I posted it just the way you're telling me.
Regardig the excel...
I worked with an excel database and so I modified the original adding my results on this way:
cuenca1$spei1<-(spei1[["fitted"]])
cuenca1$spei3<-(spei3[["fitted"]])
cuenca1$spei9<-(spei9[["fitted"]])
cuenca1$spei12<-(spei12[["fitted"]])
cuenca1$spei24<-(spei24[["fitted"]])
cuenca1$spei48<-(spei48[["fitted"]])
Then...
cuen=cuenca1 (-> I changed the name of my database because saving the modified excel with the original name, no changes were save)
write.csv(cuen, file="cuenquita.xlsx")
The final result can be seen from the screenshot.
FJCC, this is my first time asking for help in a forum (?), I was not sure of receiving an answer (but I had nothing to lose) so I am very happy that there are people ready to help and so fast!
Thank you very much!