how to select multiple values from one excel cell

I have a scenarios as a prereq.. i need to run function1,function2  then Testcase 1 

Functions are storing in Events, which trigerring from excel 

Excel - 

Single Cell -   function1,function2

on the even i provided 

if prereq == (function1)

{

run function1

}

and 

if prereq == (function2)

{

run function2

}

run testcase1 

can any one help to write a good groovy script here for this scenario