Can we skip the default values of a Global Variables and use Data Files Input to Run Test Suit ?

Can we skip the default value of a Global Variables and use Data Files Input to Run Test Suit ?

I have try to run a test suit with a global variables in it, also i have use a excel data file. But when the Test Suit run, it only use default value of Global Variables. Can we skip the default value and run with data file values. And How ?