It _may_ be (or be similar to) what's commonly known as 'door edge trim'. Try driving the van (so you can show them what you mean) to a big-box auto parts store (NAPA, or similar) and asking one of the older countermen to take a look at what you have now.
Jim, "Mo' coffee!"
'06 Tiger CX 'C Minus' on a Silverado 2500HD 4x4, 8.1 & Allison (aka 'Loafer's Glory')