This article describes how to specify a program to start a connection by using Microsoft Remote Desktop Connection.
For example, an application displays an error message when accessing through the Citrix ICA protocol. You can use RDP initial app to compare the behavior of the application.
This option works only if you are connecting to a Terminal Server or Remote Desktop Services. This Microsoft Windows role is installed on each VDA.
Below is an example to publish task manager as an RDP Remote App,
1.Create an RDP File and open it with the editor and add the following parameters:
2. Change Registry on VDA/Server which hosts the application
3. Enable following Citrix Policy via Studio or GPO
Launching of non-published programs during client connection
4. Start the MSTSC.exe with the created RDP file.
https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/cc733043(v=ws.11)?redirectedfrom=MSDN