Display leading spaces as tabs

It's been mandated that we use 2 spaces of indentation in the code, but I can't tell where the indentations are when it is that narrow. I have to click on an open brace to see where the close brace is. Anyway, what I'd love is a way to tell the editor to use a tab instead of leading spaces, but have the file actually contain the spaces, so I don't accidentally check the tabs in. That is, right now I could hit alt-cmd-L and edit the file, but then all the lines would appear changed, and I'd have to unformat the file before checking it in. Is there a way to make it look to me like I've done that with out changing the file?

Thanks!