Execute Package Utility / Set Values / How To Set Property Path And Values

Hi
I have one problem in SSIS for passing Variable Values while executing Package. I'm giving in details as below:

I opened Microsoft SQL Server Management Studio
Made Connection to Integration Services
To Execute Package I Right Clicked and Click on Run Package
Then I Clicked on Execute and package was executed successfully.

Problem is that if I try to Set Values then Package through Error
DTExec: Could not set ProcessMode value to M.

Basically I could not understand in which format I should pass the Variables.
What I tried is listed below:

ProcessMode;M
Package.Variables[User:rocessMode].Value;M
Package.Variables[ProcessMode].Value;M
But every time I got errors.

And then I tried from Command Line
DTEXEC /DTS "MSDBLoad_Order" /SERVER SERVERNAME /MAXCONCURRENT " -1 " /CHECKPOINTING OFF /REPORTING V /SET Package.Variables[ProcessMode].Value;M

First time Process run successfully. And it has changed the ProcessMode to M also. But after that it was also not changing the ProcessMode Value to M.

Please help in regarding. I tried a lot from Site examples also, but could not get proper solution.


Thanks in advance
Bhudev