update a part of a file through other file content

Hi, I am running a toolbox, where I am providing parameters along with many other values as an input file. After first estimation run, I want to update a part of my input file from one of the file content generated as an output in workspace.

My input file looks like-

 ********** MODEL STATES
 d/dt(mi) = ksyn_mi * NFKB - kdeg_mi * mi
 d/dt(M) = 0  

 ********** MODEL PARAMETERS
 ksyn_mi1 = 1
 kdeg1_mi1 = 1
 kdeg2_mi1 = 1
 ksyn_I = 0.0961
 kdeg_I = 0.0961 
 kph1_I = 1
 ********** MODEL VARIABLES
 ********** MODEL REACTIONS
 ********** MODEL FUNCTIONS

In this file, I want to replace the values inside ****** MODEL PARAMETERS and ******** MODEL VARIABLES in each new estimation run, rest of the part will remain the same. And I also want to know that how can I access the workspace output folder in my code to replace input file content?

[Jan]

What is "the workspace output folder"? The solution is trivial: Import the file, apply the required changes, write the file. A more specific question would allow to answer with more details. So please show us, what you have tried so far and explain, which problems occur.