To establish connection with remote host you have to define net service name on the local host. You can use Oracle "Net8 Assistant" or you can configure $ORACLE_HOME\NETWORK\ADMIN\tnsnames.ora file manually.
Here is an example of an entry for MYDATABASE database on SERVER_NAME remote host in the tnsnames.ora file:
#------------------------------------------------
MYDATABASE.SERVER_NAME =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = SERVER_NAME)(PORT = 1521))
)
(CONNECT_DATA =
(SID = MYDATABASE)
(SERVICE_NAME = MYDATABASE.SERVER_NAME)
)
)
#------------------------------------------------
Following entry to the dbxconnections.ini will do the rest:
[Oracle]
BlobSize=-1
DataBase=MYDATABASE.SERVER_NAME
DriverName=Oracle
ErrorResourceFile=
LocaleCode=0000
Password=password
Oracle TransIsolation=ReadCommited
User_Name=user