How to combine a "matte" .mov with the original video?

Hey all! Nice to meet you!
I am working with video in Photoshop for the first time.
I have no programs like AfterEffects etc so I try to make my first clip in Photoshop CS3 extended.
I downloaded a nice .mov of an explosion (in black background).
In the zip file there was a second version of the .mov as the matte for the explosion (white "flames" in black background).
How can I combine these two videos so that the background of the original video can be transparent?
In other words can the "matte" called video work as an alpha mask for the original video?
Does the Photoshop has this capability?

Thanks for your help in advance!