reinvoking from the tcl shell

Hello,

I'd like to reinvoke the simulation using a tcl script. Is this possible? What's the tcl command to re-invoke the simulation?

Actually, I would like a script that runs a preamble command to update the simulation options contained in the irun.f file before re-starting the simulation. That would allow me to re-start the simulation with new options without leaving simvision. 

Is this feasible?

thanks