Create an internal table from a variable

Can anyone help with the following issue that I am facing?

Requirement:

Check that a record exists in a database table:

The table name, table fields, field values are passed in a customising table

I have build the dynamic query

SELECT SINGLE *
         FROM (lw_passed_table)
         INTO lw_query_return
         WHERE (lw_where_clause).

     IF ( sy-subrc <> 0 ).
*     Pass value not found in passed table using passed parameters
*     Write error message here
     ENDIF.

The issue is lw_query_return I have to hard code the type, in this case the query will check the existance of a vendor in LFB1 so in my code I have

DATA: lw_query_return TYPE LFB1

         .

What I need to do is set the type of lw_query_return to the table that is stored in the vaibale lw_passed_table.

I have search for a long time and could not find any help with this.

Has anyone any idea how I can achieve what I need?

Thanking all in advance

Ian