Yes. I've done this. Although my post keeps getting removed.

Although not pixel-strict alignment, but almost indistinguishable from that:
Step 1:
Format Cells -> Number -> Custom -> "0.????"
Step 2:
Conditional Format ->
New Rule -> Use a formula -> "=B2=TRUNC(B2)"
Format... -> Number -> Custom -> "0 ________"
Applies to -> "=$B$2:$B$18"

Note 1: Number of '_'s is twice of number of '?'s.
Note 2: Symbol between '0' and '_' is U+2009 THIN SPACE

Although not pixel-strict alignment, but almost indistinguishable from that:
imgur: Y5DPdfS
Step 1:
Format Cells -> Number -> Custom -> "0.????"
imgur: 94q7vJH
Step 2:
Conditional Format ->
New Rule -> Use a formula -> "=B2=TRUNC(B2)"
imgur: LaTwE2Z
Format... -> Number -> Custom -> "0 ________"
imgur: GOcuE9M
Applies to -> "=$B$2:$B$18"
imgur: 953EWYh

Note 1: Number of '_'s is twice of number of '?'s.
Note 2: Symbol between '0' and '_' is U+2009 THIN SPACE (' ')

I've been looking for an answer to that question for a good while. I need a way to do this with custom number formatting and haven't found a solution. I don't have to say that often with Excel, but I don't think it's possible.

use "0.0???", to force a 0 after the decimal. "2." becomes "2.0"

Doesn't eliminate the decimal point for whole numbers.