Matei,
It is possible, but not with AMR_SOL's existing idioms.
What you would need to do is use AMRITA's replace mechanism
on the keyword flowin providing a back-end that
does what you want. The back-end would basically lift
grids {G1,..,Glmax} from the target input and
and add them to the current G0. It would probably
take me about 16 man hours to implement; 4 for the coding
and 12, or more, for the testing. Therefore it's not
going to get done this week, but I'll put it on my TODO list.
James