Linefeeds are stored as ascii character 13 and then ascii character 10.
I tried using the code
@replacesubstring(NewIntExtn; @char(13) : @char(10) ;"")
in the Input translation formula for the field but it did not work.
So I left it as
@trim(NewIntExtn)
In the end I put in the query save lotusscript:
'Remove linefeed in field NewIntExtn
tempNewIntExtn = source.FieldGetText("NewIntExtn")
While Instr(tempNewIntExtn, Chr(13))
tempNewIntExtn = Left(tempNewIntExtn, Instr(tempNewIntExtn, Chr(13))-1) & "" & Right(tempNewIntExtn, Len(tempNewIntExtn) - Instr(tempNewIntExtn, Chr(13)))
Wend
While Instr(tempNewIntExtn, Chr(10))
tempNewIntExtn = Left(tempNewIntExtn, Instr(tempNewIntExtn, Chr(10))-1) & "" & Right(tempNewIntExtn, Len(tempNewIntExtn) - Instr(tempNewIntExtn, Chr(10)))
Wend
Call source.fieldsettext("NewIntExtn", tempNewIntExtn)