In a layout you can get the viewports, (ssget "X" '((0 . "VIEWPORT")(cons 410 (getvar 'ctab)))) the 410 restricts to the current layout tab. if you have 2 Mviews the ssget will return 3 viewports as Pspace is the first viewport. So you can set a viewport as current, now where is it, then using lisp do the vplayer.
Good task for learning lisp. The steps.
Pick block 1 using entsel, get insertion point, get X1 & Y1
Pick block 2 using entsel, get insertion point get X2 & Y2
Hor dist X2 -X1
Ver dist Y2-Y1
Have a go, never to late to learn.