Cells with time-dependent concentration?

Hi, I found that time-dependant boundary conditions in flow are possible in TOUGH2 by using FOFT and GOFT blocks, but is it also possible to have a time-dependent concentration at certain element?

In my case, I assigned a large volume (10^50) to a certain cell to maintain a constant concentration during the simulation, but I want to change this concentration in time (e.g. annually changing). I know I can use RESTART option to break time span into annual pieces, but wondering if there is a way to assign this to the input file as a table before running the simulation.

Thank you.