multi project solution - how to setup

hi. I have a solution file that contains for example two website applications and one unit tests framework.
I would really like to be able to have a setup something like
Solution Name
     Continuous Integration / Unit Testing
          CI Build (automatic run / tests) ...buildagent/work/000
     Website1
          DeployToTest (dependency = CI Build) ...buildagent/work/111
          DeployToProd (dependency = CI build)...buildagent/work/111
     Website2
          DeployToTest (dependency = CI build)...buildagent/work/222
          DeployToProd (dependency = CI build)...buildagent/work/222

I am not having any issue in getting the deploys to depend on CI.
I am however having a problem in telling The DeployToX project to use the CI Build agent dir.

my setup is like this.
CI (this runs fine)
VCS Root = TFS (TFS_Server)
Build Steps (VS and Unit runner)

DeployToTest
VCS Root = TFS (TFS_Server)
MSBuild = Compile website1.csproj based on agent 000 data.
     filepath = root/dir/custom.msbuild
     target = /P:targetEnv=Build
     working dir = Null
MSBuild = Deploy Compiled website to IIS servers
       filepath = root/dir/custom.msbuild
       target = /P:targetEnv=DeployTest
     Working dir = null

Problem is that I am just not able to get the 000 build agent data from the other project. Any suggestions? Is there something I need to be setting in working dir or build file path to make sure I am refering the data in 000 builldAgent?