Inserting data into PostgreSQL

How can I inserting data from a file into PostgreSQL? I've tried the
following SQL command, but it didn't work:

INSERTO INTO table_name (column_name[, ...])  FROM FILE 'file_name' (data_type, ...)

I received the message:

ERROR:  parser: parse error at or near "from"

Besides, which caracter must we use to separate the columns into the file?
I used ",". Is it correct?

Thanks,

Rodney.