You can query and update information in an Excel spreadsheet using ActiveX Data Objects (ADO). http://support.microsoft.com/kb/q195951/
But, it's heavy and complicated mehanizm to use it inside of QTP.
The better way:
1. Use Excel Automation object for easy retrieving data from external Excel file.
Set XLApp = CreateObject("Excel.Application")
Set XLBook = XLApp.Workbooks.Open(sFile, readOnly=False
Set XLSheet = XLApp.ActiveSheet
XLSheet.Name = "Global"
YourVARIABLE = XLSheet.Cells(1,1).Value
2. Use built In QTP mehanizm of communicate with data in Excel format: QTP DataTable
Think about your task a little bit differently:
try to integrate (Load) first Excel as DataTable, retrieve data from, start another Test, that integrated with another Excel in DataTable...
Something like that.
If you need more detailed help, please,
post detailed task and description, what exactly you want to implement. Not HOW - but WHAT.
But try it by yourself first :-}