Thanks a lot Helen it now works for me.

> Take out ".dll" unless your UDFAccess setting in firebird.conf is

FULL (not recommended, as this makes your database
platform-dependent). Leave the default setting in firebird.conf as

> #UdfAccess = Restrict UDF
> and locate your dll in the UDF directory beneath the Firebird rootdir.
>
> (You'll need to drop and redeclare the UDF), with commits after each):
>
> DECLARE EXTERNAL FUNCTION F_BLOBMID
> BLOB,
> INTEGER,
> INTEGER
> RETURNS CSTRING(8190) FREE_IT
> ENTRY_POINT 'blobmid' MODULE_NAME 'FreeAdhocUDF_borc5_32';
>
>
> ./heLen
>