Creating changing variables in function workspace

Dear all,

I am trying to create and save some structure into a auto generated variables. I am lost as to how to assign a new variable name from this auto generated lists.

%Step 1: Create a structure.

m.a = 1; m.b = 2;

%Step 2: Create a variable name from my folder number that I have inserted into this function.

varName = [ 'dirA_' num2str(dirAname) '_dirB' num2str(dirBname) ];

%Step 3: The new variable name is whatever varName is.

[ 'dirA_' num2str(dirAname) '_dirB' num2str(dirBname) ] = m;

%Step 4: Save the folder to the directory;

I am stuck on the last stage. Any help will be much appreciated.

Rules: I can not let this variable go into my matlab workspace. It has to be in this function workspace and disappear as long as the job of this function is closed.