[plt-scheme] String escape sequences hurt!

Hi all,

I'm having a problem with developing of slides.
I've developed a module which I sent to the list sometime ago which
generates latex formulas so they get inserted automatically in a
slide. The big problem is that one has to typeset the latex code as a
string for example:
(latex-formula "x^2") will insert the latex formula with x squared in
the same way (bitmap ...) would insert a bitmap image. The problem is
evident if I try to typeset an equation or other command:
(latex-formula "\sum_{i = 1}^10 \varphi i^\theta")
will not work since \ is interpreted as an escape sequence. So I've
been typing something like:
(latex-formula "\\sum_{i = 1}^10 \\varphi i^\\theta")
all the time, which is error prone and very ugly... but I have not had
the time to search how to disconnect the escape chars. I don't this is
possible to do in a straightforward way, still I think it would be
nice to latex-formula to catch the raw string and then insert
automatically the escape characters for the delight of plt-scheme. I
would like suggestions, oppinions, help! :)

Thanks a lot,

--
Paulo Jorge Matos - pocm at sat inesc-id pt
Web: http://sat.inesc-id.pt/~pocm
Computer and Software Engineering
INESC-ID - SAT Group