Thank you, vbaInet for your prompt answer.
The field name is ENTRADA, and the data are taken and selected from a Table named RESULTADOS. The field is text, and there´s only one other field that is text, which is CódECR. All other fields are numbers, but none of them are calculated in this query. They´re just selected from the Table RESULTADOS.
When I export this query to a txt file, the field ENTRADA will show up only if its located at the end of the query. The SQL command follows. The field shows nicely in ACCESS but I cannot get it into the txt file.
SELECT RESULTADOS.CódECR, RESULTADOS.PAR, RESULTADOS.Rep, RESULTADOS.TRAT, RESULTADOS.REND, RESULTADOS.ENTRADA
FROM ([ENSAYO ELEGIDO] INNER JOIN ENSAYOS ON ([ENSAYO ELEGIDO].CódECR = ENSAYOS.CódECR) AND ([ENSAYO ELEGIDO].LOCALIDAD = ENSAYOS.LOC)) INNER JOIN RESULTADOS ON ENSAYOS.CódECR = RESULTADOS.CódECR
WHERE (((RESULTADOS.TRAT)<1000))
WITH OWNERACCESS OPTION;