If you want to do this using a regular expression, I would suggest something like this:
regsub -all {ZZ00.(.*)} $var1 {1} var2
where your original string is in $var1 and the result (everything after the period) will be put in $var2.
The regex to match the pattern is ZZ00.(.*) which says look for ZZ00 followed by a period and then capture anything after the period. Then you are taking that saved capture 1 and placing it in $var2.
-jamin
