Crystal Reports formula to retrieve values from 2 different table

Message

I have this problem.
 In a table that I put in a report I have 2 fields: LinkType and Code
 Depending on the content of LinkType, the report would like to see a description that must be retrieved from several tables using value as a code.

 Here's an example:
 LinkType = 1 and Code = 15 
 LinkType = 2 and Code = 15
In the first case I would like to see the description on the code 15 taken from Table 1.
 In the second case I would like to see the description on the code 15 taken from Table2.

 Is there a function to do this (I was thinking of a kind used as DLookup in Access) or is it better if I prepare the data in a temporary table (using my VB project )and I base the report on the latter?

 thanks

Edited by patapatty - 21 Sep 2011 at 11:01pm