Unbound text box, Text > 255 characters, MSAccess/PostgreSQL

Hello.
I have the following problem with MS Access/PostgreSQL combination:
There is a form in Access that has an unbound text box, used for entering a commentary of a batch of records.
There is a DAO Append Query that has a parameter that is passed from the text box using parameter of DAO QueryDef object.
I adjusted B7 parameter (Text as LongVarchar) in connection string (ODBC driver) to 1, so that Access links PostgreSQL Text fields as Memo fields in Access. The intention was to be able to enter unlimited length commentary into the field.
But, although I can enter unlimited text by using bound text box in some other forms, in this particular form I can't use bound control, so I need to pass text from UNBOUND control to the linked table by using DAO or ADO code. It seems that DAO query can't accept Memo as parameter, but only text. If my text exceeds length of 255, I have an VBA error 3271. If text in unbound text box is shorter that 255 everything is OK.

So, is there any way to pass text of length >255 from unbound text box to Memo field of linked PostgreSQL table, by using DAO or ADO ?

Thanks in advance,

Zlatko