is it possible to use semicolon instead of comma in MVZIP??
no it is not possible. This is the error you will get:
Error in 'eval' command: The expression is malformed. Expected ).
If you mean "can I use semicolon to separate the data from the two zipped multivalue fields ", then the answer is yes.
| eval mydata=mvzip(Field1, Field2,";")
Using the above on Field1 which has value...
...and Field2 which has value...
...results in a multivalue field named mydata with...