Here is one more
with t(v) as ( select '0008.22816' union all select '069.3142' )
select
[formattted] =
replace(str(parsename(t.v,2),7),' ','0') + '.' +
replace(str(parsename(t.v,1),7),' ','0'),
*
from t
Also, be aware that all presented solutions will fail or loose data if there will be more than 7 digits.
To avoid it some extra moves should be done.