foam-extend4.1-coherent-io/tutorials/lagrangian/icoLagrangianFoam/channelParticles/customRegexp

particleNum
{
    theTitle "Number of particles";
    expr "Current number of parcels + = (%f%)";
    titles ( nr);
}
particlesAdded
{
    theTitle "Particles added";
    expr "Added (%f%) new parcels";
    titles ( nr );
}