Access 2003 / SQLSEE 2005 - Using Forms To Filter Recordsets

I upsized an Access 2003 database to SQL Server Express Edition 2005, and have converted all tables, queries, reports and macros successfully so far. The snag I'm running into involves using macros embedded in buttons on certain forms using Access as the frontend.

With these forms, the idea is to navigate to a certain record, and hit a button to bring up a print preview view of a report. Based on the record you're looking at in the form, it should check against the data in the table to which it refers, and pull up a single record in the report.

In access as a standalone, using the OpenReport command, the code was as follows:

[MRB Report Data]![MRB Report Number]=[Forms]![MRB Data Input]![MRB Report Number]

MRB Report Data is the table containing data, and MRB Report Number is the primary key (autonumber). MRB Data Input is the form in question, and the second MRB Report Number is the control field that references back to the MRB Data Input table.

When I try to run this using Access as a frontend, an error occurs at the first '!' - is there a different syntax I need to specify to reference a form in this case?

Thanx in advance.