using dummy variable

[purishiru]

Hello, I need help.

I am new in both eviews and econometrics. Help will very much appreciated.
1. I am doing a panel data study for my thesis, and one of my 5 variables is a dummy of a Mod, which consist of three : A,B, C. one of the three will be represented by intercept (C), however. so that leave another two.
the dummy is for Mod(A,B)
I have tried several ways suggested by the forum, but i keep getting error message.
if i use Genr - generate series by equation - enter @expand(Mod); - it show : @EXPAND is not a genr or series expresion function , if I put equation
e.g. roe c gdp cpi @expand(Mod) or roe gdp cpi @expand(Mod); - it says: syntax error
I have tried to write : roe c gdp cpi Group 01 @expand(Mod)
its not working.

2. I need it for a regression in which i am using a pool. can the dummy equation and pool use together? or maybe an alternative so the regression could work as one.
3. is it possible to have the dummy input together in imported excel and have it worked?

I can´t find these on internet.
can someone please help me out??

I am very new to this,as I have acquainted with eviews only for a month. It would be great help if the explanation can go step by step.

Thank you in advance for save me here!