directly exporting report through custom button

[Guru]

Hi All,

I am having a custom report in crm for case. To export this report to
word format we have to run the report and export.
to avoid the number of clicks, we created a custom button to export
this report directly without running the report.

We took the report url from reportserver and made the click event in
button to export the report.
This function is working fine in On-Premise environment. This same
functionality is not working in IFD configured environment.
In IFD environment i am not able to export the report directly.

Thanks in advance,
Siva