Is it possible to specify a format with a minimum and maximum number of decimal places?

Some example inputs and outputs (for minimum 2, maximum 4):

1000 => 1000.00
1000.1 => 1000.10
1000.123 => 1000.123
1000.1234 => 1000.1234

Ideal would be to optionally allow just the minimum, so with minimum 2
1000.1 => 1000.10
1000.1234567 => 1000.1234567

I've tried this with the old style format string, but it doesn't appear to work (I'm using thousand separators, but that doesn't appear to make a difference when they are removed)

0,0.00[0000]