>Does anyone know how I can do an extensive seek. Something like:
>Seek (birthd) and patname.value = tablename.fieldname and etc etc

Use LOCATE rather than SEEK, which can use existing indexes to fully or partially optimize an expression involving multiple fields, each having its own tag. This will spin through the file in the current index order.

or if you have a few fixed composite lookups create index tag(s) based on multiple fields; generally, this will involve concatenating string values together to create the index; something like:

INDEX on DTOS(birthdate)+some character field TAG ComplexNDX

Now, to do a lookup:

SET INDEX TO ComplexNDX
SEEK DTOS(birthd) + pathname.value

This will order things by the complex expression.