Connect a set to an existing model's variable

I have a dynamic single country CGE model implemented in GAMS. I am trying to change the region of interest for the model. By doing so, additional data exist which i try to connect to the
already stated variables of the model (exogenous variables).

In this regard, I want to introduce a new set for the import and export margins (“t-R1Greece”:import margins and “M1Servi_pvst”:export margins), and
connect this set with the respective variable of the model tmg(i,n,t):Trade and transport margins, that handle this data. Where, i : the commodities of the model , t:the time dimension and n:

  set n Transport nodes /
   d  Domestic
   x  Export
   m  Import
/ ;

I need your validation on the following attempt to implement it.

a) I begin by introducing a new set (marg) for reading the margin data from the SAM table, as follows(where “is” the set for SAM table):

Set marg(is) Margins / t-R1Greece 
                       M1Servi_pvst / ;

b) I connect the new sets with tmg through the already stated set “Transport nodes”, as follows:

Set m(marg) import margins/ t-R1Greece /;
Set e(marg) export margins / M1Servi_pvst /;

Therefore, every equation that contains tmg is read the respective data through m and e. For example:

pm(i,t) =e= pmd(i,t) + pmarg(i,t)*tmg(i,"m",t) ;

How closely am I? Could anyone give me a direction?

Thank you in advance.

Hi
You don’t need the subsets in this case. You could just write:

pm(i,t) =e= pmd(i,t) + pmarg(i,t)*tmg(i,"t-R1Greece",t);

I hope this helps!
Renger

Mr Renger thank you for your reply.

I will consider your feedback.