I have been searching and googling for hours and hours trying various example but cant get anything to work.
Reading serial data and storing it is easy, when the data is properly delimited, as yours is.
Parsing the data into command and value tokens is trivial, using strtok().
Comparing the command against a known set of commands is trivial, using strcmp().
Storing the value token in EEPROM is trivial. Converting the value token to a value is trivial, if that is what you want to do. Storing the value in EEPROM is trivial
So, it's hard to imagine what part you have problems with. Nothing in your code looks wrong.
Of course, nothing looks right, either, seeing as how you didn't post any.
Can anyone suggest a simple solution.
Sure. As soon as you've suggested a simple problem. "I want to read serial data, parse it, and store something in EEPROM at some undefined address" isn't a simple problem. Complex problems do not have simple solutions, until you break the problem down.