subst ?-nobackslashes? ?-nocommands? ?-novariables? string
If any of the -nobackslashes, -nocommands, or -novariables are specified, then the corresponding substitutions are not performed. For example, if -nocommands is specified, command substitution is not performed: open and close brackets are treated as ordinary characters with no special interpretation.
You may have [} etc in the string. I would use all three flags unless there are commands in the string you want to ececute
set sUUData [subst nobackslashes -nocommands -novariables $sUUData]
.
