Use a Tcombobox in OwnerDraw mode..
Populate the list with the Visible Text = HiddenText;
When painting the list only paint the TEXT for each cell that gets called for a paint job.
For example of one line
Manzanas=M1
And using the items you can look at the KEYS and VALUES array
so when painting each item you paint only the KEYS and when the user select the item you can use the VALUES to obtain the M1 for example..