LOV with ID and meaning

Hi All

I need to build and LOV that must show the user the Tax Registration Number and the Supplier Name so that when user select the entry only the Tax Registration Number will return into the WEB document that they are busy capturing to.

We have a custom table that stores these values i.e.

Column 1 = Tax Registration Number

Column 2 = Supplier

Column 3 = Vat Number

Now as the user is completing the WEB ADI document one of the columns required to be completed is that of Tax Registration Number, but in order to select the correct tax reg number they must be able to see that the tax registration number links to supplier XXX.