Dummy in GMM

[Dovemark]

Dear guys

I am doing research about the difference in dividend policy between the usa and europe. My problem is the following: I want to do a dynamic programming model: GMM and I want to use a dummy variable, but eviews (my dummy takes the following values: 1 for europe and 0 for usa) keeps giving me the message "near singular matrix" when I want to use GMM. I know that is because my dummy is constant over my cross section. Is there a way I can solve this problem (easily, because my knowledge of eviews is lilmited)
Thanks

[Dovemark]

Just to be complete this is my equation: Dividendyield in year t= dividendyield t-1+ age+ age*dummy+size+size*dummy+... and so on