As you mention its an OLE DB connection the database settings etc would be stored as a string inside the script of your QlikView QVW document you've made (or been given).
You might need to check that the user account running your QlikView Server services on the server has access to the required databases to read the data.
Also check the help in QlikView, search for 'Loading Data from Databases' as it has some useful pages and links.
from ur application follow these steps,
2.Data (Data tab in bottom)-select OLEDB as ur Database if ur database is OLEDB
3.Connect (click connnect)
4.Select ur proper driver from DataLink Properties& Provider tab
ex:Microsoft OLEDB provide for SQL server (thse u have to choose if u want o connect sql server db)
5. Next (Click Next)
6. Select ur servername
Enter username and password in 2
or if u have NT details from 2 option use radio button as "Use Windows NT iNTEGRATED sECURITY"
7.select ur databse
if connection is success then automatically u will get connection srting in ur edit script.