Check if a column contains a substring

[#1]

I would like to create a new column in using jsl based on a condition that involves 2 columns. I could describe in ordinary language it as follows:

New Column( "Condition",
        Character,
        "Nominal",
        Formula(
            If(  Column A contains substring "REF" then return Word(4, Column B, "_")
            else return Word(4, Column A, "_")
               )
        )

could you help me with the syntax in the if statement?

[#2 · Accepted solution]

If(Contains("A_B_C", "B"),
	Word(1, "D_C", "_")
,
	Word(2, "A_Z", "_")
)

is an example using Contains and Word. Replace hard-coded strings with your character column references