It depends on whether that decimal and zeros exist in the source file. If they don't, then when you're importing, use the wizard, and stop at the point where it shows the field types, and either change the field type to Text or Double--if you're sure the data is all numeric, then use Double.
Then in the result table, you can format that field (if it's a double) to show decimals only when they exist (auto), which I believe is the default for the double field type.
--Jim