[mpich-discuss] MPICH under torque - adding new nodes

Hello, I want use MPICH under the Torque RMS. I can see that mpiexec will automatically take the nodefile from $PBS_NODEFILE. I am working on dynamically adding nodes to an existing job in torque. So there might be a point where the job actually has more number of nodes than what was listed in $PBS_NODEFILE. Is it possible to do an MPI_Comm_spawn on these new nodes (which is not listed in PBS_NODEFILE but is actually a part of job)? For example using some info argument such as add-host or something? Or if it entails that the PBS_NODEFILE must be changed with the newly added nodes, I can do that too. But the basic question is, can MPICH spawn processes on these newly allocated nodes for the same job through some mechanism? Best, Suraj