Formatting of digits across columns

[João Rodrigues]

Dear list members,

I want to write a matrix with real numbers to an ASCII file so that the 
maximum number of digits is always approximately the same and in each 
column the number of decimal places is the same.

For example, if n = 4:

17.6        3.01          6.754
70.0        4.27           0.294
196.0      15.03         0.043

I can do something like:

dlmwrite(matrix,"delimiter", "\t", "precision","%10.2f") but then I need 
to know exactly how many decimal places there will be, and the same 
value will apply to all columns.

dlmwrite(matrix,"delimiter", "\t", "precision",4) will yield a maximum 
of 4 digits per entry, but will not fill in the extra digits so that the 
number of decimal places per column is always the same.

A simple fix, someone?
Thank you,
Joao