Field Concatenation in a single table

Tech-Archive recommends: Fix windows errors by optimizing your registry

I have imported 160,000 records from an Excel file into an Access table
called "Vendor Master". The Vendor Master table has 3 fields, all text, that
I would like to combine into 1 field to be used as a key field.

I created a new field called "VIN" to combine the 3 other fields, but can't
seem to get the expression right......... if in fact I should be even using
an expression?

GIVEN INFO: Database Name - CSU
Table Name - Vendor Master
Field#1 Name - PRE
Field#2 Name - FEID
Field#3 Name - EXT

My failed expression in default value: =[Vendor Master]![PRE]&+[Vendor
Master]![FEID]&+[Vendor Master]![EXT]

I keep getting an error message saying that Access can't find my field
names? Where did I go wrong?

HELP! HELP! HELP! HELP!


.