The ornamental design for a mobilecomputerstand, as shown and described.
FIG. 1 is a perspective view from the front and left side of a mobile
computer stand, showing my new design, the broken lines are for
environmental purposes only and form no part of the claimed design;
FIG. 2 is a perspective view from the front and right hand side of the
computer stand;
FIG. 3 is a perspective view from the back and left hand side of the
computer stand;