Hopefully no one has taken on this job.
I was interested in it and wrote a script in a few minutes which does the job.
However you did not specify if the folder where the images are is static or not and if the image format (wildcard) is static or not.
So here is a code which uses a specific folder and a specific image format:
Code:
// ============================================================================
// VARIABLES

var nro_images = 0;
var cur_image = 0;


// ============================================================================
// STRINGS & TEXT

string current_image = "#100";

text image_file
{
	strings = 100;
}


// ============================================================================
// PANEL

panel image_pan
{
	pos_x = 100;
	pos_y = 100;
}


// ============================================================================
// FUNCTIONS

// sets the current_image string and updates the panel
function update_image()
{
	str_cpy(current_image,"images\\");
	str_cat(current_image,image_file.string[cur_image]);
 	
	image_pan.bmap = bmap_create(current_image);
	image_pan.size_x = bmap_width(image_pan.bmap);
	image_pan.size_y = bmap_height(image_pan.bmap);
}

// shows the next image
function cycle_imagesUp()
{
	cur_image = cycle(cur_image+1,0,nro_images);
	
	update_image();
}

// shows the previous image
function cycle_imagesDown()
{
	cur_image = cycle(cur_image-1,0,nro_images);
	
	update_image();
}


// loads the images with a specific format from a specific folder
function load_images()
{
	nro_images = txt_for_dir(image_file,"images\\*.jpg");
	
	update_image();
}


// ============================================================================
// END OF FILE
// ============================================================================