how MOVX can be used in high level programming

hi, i am a student i am doing a project where i m using simeple romless 8051 uc.here i m using 64kb programme and 64kb data memory space. from my programme code i am reading an external hex file which is loaded in 64kb data memory can anyone tell me how can i specify programme and data space in keil compiler and how can i tell programme code that file ur reading is in data space. basically i have to read movx instruction to read file but how can i differenciate in highlevel programming in compiler.