Conditional Source Expression with Concatenation as output

Summary:

We are migrating HFM Import scripts to cloud. I am planning to leverage Conditional expression to achieve similar functionality but it is not working.

Basically we plan to concatenate couple of columns depending on the condition. I am unable to concatenate two values . I am getting error.

if (split(RECORD,"|",6) !="" and UD4 !=null) return "UD4 + split(RECORD,"|",6)"
else return split(RECORD,"|",6)

I tried Concat("UD4|split(RECORD,"|",6)","_") but both options did not work.

I would appreciate if could anyone provide sample for concatenated two columns in source expression.

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