autofill fields based on xml list

I have created AdobePro XI form and need to auto populate other fields (can be text fields) based on the selection of a drop-down field.

So drop-down field (A) when selected auto fills field (B) and (C) with connected information.

Field (A) = Site Name, Field (B) = Support Team, Field (C) = Number to call

I can use the export value from (A) to display in (B) but that won't work to populate (C)

I have a list created in Excel and converted to an xml data list with schema. I can import the xml, but then not sure where to go from that point.

Any help, advice would be greatly appreciated.