Formatting issue in writing text file by open dataset

Hi all,

I want to write a text file with this format:

Col1 | Col2 | Col3 | Col4

abcdef | 1 | 2005.02.01 | 144

bcd | 134 | 2005.07.01 | 24

How could I keep the content displayed in line with the header?

p.s. Currently I could only write the content like this:

Col1 | Col2 | Col3 | Col4

abcdef | 1 | 2005.02.01 | 144

bcd | 134 | 2005.07.01 | 24