makros in photoshop?

Hi,
I need some help. I have to edit ca.2000 pictures and in all this pictures I have to do the same action. I found the "action" function in ps, so ps makes a sequence of actions only by pressing one key. But there are still some problems.
I work with a mask, and 2 pictures (A and B). Picture A should be transparent for B in the area of the mask.
To be more precise:
-I load mask, picture A, picture B
-then i ensure that all pictures are on the same "modus"
-I choose the function "channel evalutaion" (i dont know the right term in english), choose the mask as mask, and source 1 and 2
-the output (a picture where one part of B and the rest of A is displayed) I save in a new file in folder XY

So far it worked with the action function, but the problem is that it will always load the same two pictures, but it should load other pictures. To figure it out: I have folder A (with pictures A1,A2,A3,A4 and so on) and folder B (with pictures B1,B2,B3,B4 and so on). Now it would be nice when it takes first time A1+B1+mask and combine then, load the second time A2+B2+mask etc.
Or is it possible that ps dont choose always the same two pictures, and work with those who are on the screen?
With "save" its the same, can ps automatically save the "output" picture in folder not using always the same filename (that one used when the action was recorded)?
I hope you understand the problem and can help me.

Hello,
If you use source channel from the same image, exclude openining it from the action (you can do it manually, right?).

Then open either Batch (File > Automate > Batch) or Image Processor (File > Scripts > Image Processor) > choose source and destination folders > choose action to play > Run.

k thx for the inputs. but the batch-thing dont work for that problem. anyway i decided to do the work manually.