>How can I duplicate the following code using the seek command:
>

> SCAN
> SELECT Invoice
> LOCATE FOR in_code = lnCustCode
>   DO WHILE FOUND()
>     do some code
>     CONTINUE
>   ENDDO
> SELECT sometable
> ENDSCAN
>

>
>The is extremely slow as this codes is already in another loop and therefore a locate for the whole table is execute each time.

If you have an index on in_code in invoice the locate will become much faster. Caching will then also improve the performance of subsequent LOCATEs in the next run of the outer loop.

Although, the seek will be faster yet. If you can get sufficient performance by just adding the in_code tag, don't bother changing the code.