Sam,

There's no reason to use it in the first place so what the difference if it works or not? :)
The following would work as long as the table in the current work area is not at EOF. The REPLACE..IN doesn't have such problem.

lcMyAlias = "MyAlias.MyField"
REPLACE (lcMyAlias) WITH "My Value"

>
>As always you have the solution. But I was looking for a reason why the second one doesn't work.
>

>>
>>The correct way is to use IN clause

>>lcMyAlias = "MyAlias"
>>lcMyField = "MyField"
>>REPLACE (lcMyField) WITH "My Value" IN (lcMyAlias)
>>