Deploying the Citrix receiver to multiple workstations via group policy is plausible.  However, the MSI file needed is not something Blackbaud Hosting has access to, and would be under the scope of Citrix Support.

Please consult Citrix Support regarding this process:

Citrix Support Page: 

Note: We provide links to third-party websites in an effort to help you resolve your issue. We are not responsible for the information on third-party websites, and we cannot assist with implementing resolutions from these websites.
Please contact the appropriate software vendor or IT professional for assistance with this process or issue, which is beyond Blackbaud's scope of support.