Looks like VFP parser got confused. Use SEEK() function instead of SEEK command.

llFound = SEEK (lcDateSet, 'tinspset', 'dateset')

>I get the following error:
>
>"SEEK (lcDateSet) ORDER TAG 'dateset' OF 'tinspset' IN 'tinspset'"
>Expression evaluator failed.
>
>I have a table named tinspect.dbf inside a dbc
>it has a corresponding tinspect.cdx
>I have a candidate index on that table named: dateset
>
>here is my exact code:
>LOCAL lcDateSet
>lcDateSet=ALLTRIM(this.getvalue())+'.'+ALLTRIM(ttool.ftoolset)
>
>SEEK (lcDateSet) ORDER TAG 'dateset' OF 'tinspset' IN 'tinspset'
>
>thisform.requery()
>***********end of code
>
>lcDateset evaluates to '10/01/2002.001.2' which should equal one of the index values.