There is a way to use your 32-bit ODBC driver on a 64-bits operating system. But I don't know if there is a 64-bit driver available yet. I'm not very sure about this but I think an old (32-bit) Interbase database only supports 32-bits drivers. We have the same problem accesing one of or DB's, but luckyly I can use a 32 bits driver and the advantage is that the reload can receive 4GB (instead of 2GB or 3GB) because of the 64-bits operating system. There is also a 32-bits ODBC management console available in a 64 bits operating system, you can find it here: \WINDOWS\SysWOW64\odbcad32.exe.
I think you should copy your 32-bit driver dll files to the same (SYSWO64) directory. After this you can use a register script (reg file) with contents like these:
Windows Registry Editor Version 5.00
For the exact content you can look at the standard register structure of your 32 bit driver on a 32 bit operating system.
As Mark says, it isn't a problem to use a 32bit ODBC driver on a 64bit OS. When you create .qvd's from your data before loading it into your end-application performance will not be affected.
If a .msi installer is provided with the driver, hacking like Mark's script should not be necessary.. After installation the 32bit ODBC source isn't visible in your standard 64bit ODBC admintool, you should use the 32bit ODBC admintool instead. You can find this at C:\WINDOWS\SysWOW64\odbcad32.exe..
If you are planning to use Publisher to pull data through a 32bit ODBC connection mind using the 32bit Publisher!!!