Another option would be to use the Tk::place geometry manager, which has x,y placement:

-x => location

Location specifies the x-coordinate within the master window of the anchor point for $slave widget. The location is specified in screen units (i.e. any of the forms accepted by Tk_GetPixels) and need not lie within the bounds of the master window.

-relx => location

Location specifies the x-coordinate within the master window of the anchor point for $slave widget. In this case the location is specified in a relative fashion as a floating-point number: 0.0 corresponds to the left edge of the master and 1.0 corresponds to the right edge of the master. Location need not be in the range 0.0-1.0. If both -x and -relx are specified for a slave then their values are summed. For example, "-relx=>0.5, -x=-2" positions the left edge of the slave 2 pixels to the left of the center of its master.

-y => location

Location specifies the y-coordinate within the master window of the anchor point for $slave widget. The location is specified in screen units (i.e. any of the forms accepted by Tk_GetPixels) and need not lie within the bounds of the master window.

-rely => location

Location specifies the y-coordinate within the master window of the anchor point for $slave widget. In this case the value is specified in a relative fashion as a floating-point number: 0.0 corresponds to the top edge of the master and 1.0 corresponds to the bottom edge of the master. Location need not be in the range 0.0-1.0. If both -y and -rely are specified for a slave then their values are summed. For example, -rely=>0.5, -x=>3 positions the top edge of the slave 3 pixels below the center of its master.