[Zope] ZSQL Method: Update using a list as an argument

I have a zsql method that takes 3 arguments (value1, value2, value3) I would like value3 to be a list for an "in" where clause. value3 is taken from a textarea form element. the sql method looks like this: update sometable set field1 = <dtml-sqlvar value1 type="int">, field2 = <dtml-sqlvar value2 type="int">, where <dtml-sqltest value3 op=eq type=nb multiple optional> of course the above is not working. My question is what type of argument do I have to pass in order to have a where clause look like where field3 in ('text1', 'text2', text3',,,) Thanks Hara