So a separate letter layer for each that you would then like to group into a "word"?
i.e.:
d
r
o
w
into:
Group 1
d
r
o
w
So then you would select these layers and make a group from the selected layers? Have you tried the native command to do this under Layers panel menu > New Group from Layers?
Or is it that the letters are not in sequential/contiguous order and New Group from Layers is lacking?
Can you post a screenshot of your layers panel?