Here's what I would do...
Create a number parameter in each component called something like ORDER. Give the parameter the value you want for assembly order.
Create your BOM table like you normally would, but instead of creating a column for rpt.index, use asm.mbr.order.
By default, the components will be listed in alphabetical order, but if you Sort by the ORDER parameter, they'll be listed in the order you want, and if my thinking is correct, the rpt.index should correspond to this parameter now, so the BOM balloons should correspond as well.
Create a number parameter in each component called something like ORDER. Give the parameter the value you want for assembly order.
Create your BOM table like you normally would, but instead of creating a column for rpt.index, use asm.mbr.order.
By default, the components will be listed in alphabetical order, but if you Sort by the ORDER parameter, they'll be listed in the order you want, and if my thinking is correct, the rpt.index should correspond to this parameter now, so the BOM balloons should correspond as well.