[rules-users] Decision table problem

Hey I am using drools with a decision table (XLS). One of the conditions in the table is a call to a java method, c.checkFoo($1,$2)), where c is of type Foo. When I first created this method it took 2 integers and that worked fine, now I need to update it to take to strings instead. I have updated the method but when trying to it I get some errors. Some examples of values in the cells for this condition are [ 901, 910 ] [ 90AAA, 90ABC] For the first value I get this error: The method checkFoo(String, String) in the type Foo is not applicable for the arguments (int, int) For the second value I get this error: The method checkFoo(String, String) in the type Foo is not applicable for the arguments (int, int) Syntax error on token "AAA", delete this token Syntax error on token "AAC", delete this token How do I convince drools that the values in the cells should be read as strings and not integers? Kind Regards Alex