"I'm trying to write this statement using eval as follows : Energy_H_A1S1 = ..."
And that is the start of your problems.
Forcing meta-data into variable names makes acessing your data complex, slow, inefficient, and buggy... as your question demonstrates. Meta-data is data. Data should be stored in variables, not in variable names.
Your poor data design forces you into writing bad code, which could be easily avoided by storing the meta-data correctly.
