A programmer (130, 135, 140) for a stimulation system for providing electrical stimulation to treat a patient, the programmer (130, 135, 140) including: a communication unit that communicates with an electrical stimulation generator to program electrical stimulation, a display screen that displays an image of a spinal column and a position of the at least one medical lead relative to the spinal column, and a user interface, wherein the programmer (130, 135, 140) determines a position of the implanted medical lead with respect to the spinal column, an initial stimulation field, and an initial target stimulation area within the initial stimulation field; displays the medical lead, the initial stimulation field, and the initial target stimulation area on the image of the spinal column, wherein the initial stimulation field has an initial boundary depicted on the display screen and the initial target stimulation area has an initial target boundary depicted on the display screen; and programs the electrical stimulation generator to generate electrical stimulation with the implanted medical lead according to the determined stimulation parameters; and wherein the programmer (130, 135, 140) receives, via the user interface, graphical manipulations of the initial boundary and the initial target boundary to define an altered stimulation field and an altered target stimulation area, wherein the graphical manipulations at least one of move and alter the shape of the initial boundary and the initial target boundary; and determines stimulation parameters to drive the implanted medical lead to generate the altered stimulation field and the altered target stimulation area, characterised in that the graphical manipulations of the initial target boundary and the initial boundary are independent of each other. a communication unit that communicates with an electrical stimulation generator to program electrical stimulation, a display screen that displays an image of a spinal column and a position of the at least one medical lead relative to the spinal column, and a user interface, determines a position of the implanted medical lead with respect to the spinal column, an initial stimulation field, and an initial target stimulation area within the initial stimulation field; the implanted medical lead with respect to the spinal column, an initial stimulation field, and an initial target stimulation area within the initial stimulation field; displays the medical lead, the initial stimulation field, and the initial target stimulation area on the image of the spinal column, wherein the initial stimulation field has an initial boundary depicted on the display screen and the initial target stimulation area has an initial target boundary depicted on the display screen; and programs the electrical stimulation generator to generate electrical stimulation with the implanted medical lead according to the determined stimulation parameters; and wherein the programmer (130, 135, 140) receives, via the user interface, graphical manipulations of the initial boundary and the initial target boundary to define an altered stimulation field and an altered target stimulation area, wherein the graphical manipulations at least one of move and alter the shape of the initial boundary and the initial target boundary; and determines stimulation parameters to drive the implanted medical lead to generate the altered stimulation field and the altered target stimulation area, characterised in that the graphical manipulations of the initial target boundary and the initial boundary are independent of each other.