Matlab: leading 0's

For adding leading zeros to a number the following can be used for 4 decimal places with integer input:

dat = 1;
sprintf(['%4.4d'], dat)

To make this programmable the following can be used:

dat       = 1;
min_width = 4;
sprintf(['%',num2str(min_width),'.', num2str(min_width),'d'], 1)

For string inputs you need:

dat       = '1'
min_width = 4;
sprintf(['%0',num2str(6),'s'], dat)