I don't use DRs but from the help file it would appear you are correct
Digital Register Block Example
You can display multiple I/O points with a Digital Register block by adding Data links to a picture. The data source you enter is a specified number of values past the block's I/O Address. You can enter A_ or F_ values in the data source, according to your needs.
For example, suppose the poll record you want to access starts at address 4001:0 and this record is composed of 16 bits (4001:0 to 4001:15).
To access this poll record, you enter 4001:0 as the block's I/O address. Then you can create Data links to access individual poll record values by entering an A_ or F_ field as the data source. For example, to access the 9th bit in the record, you would specify the 8th element past the I/O address. As a result, you would enter A_8 or F_8 as the field in the data source.
Likewise, if the I/O address of the poll record is 1075:0 and you want to access the first value, use the field A_0 or F_0 in the data source.