There are two ways that I know of. The first is to create an alias that you use in your select statement. The alias is a permanent object. An alias is created using the SQl command:
CREATE ALIAS AliasName FOR library/file (member)
Use it in a select statement:
SELECT * FROM AliasName
The second way is to issue an OVRDBF command specifying the file and member:
OVRDBF FileName TOFILE(FileName) MBR(member)
Then, in your program, use it with a standard select against the file name.