sed - escape character

I've a sed command that looks like below:
QSH CMD('sed -e "s?&1? <\\MCBELL4\BossTemp\NewAccount\LHCTEST2ERROR.csv>?g"
/tmp/SVEML_PALHC_MSRL3E144A_962203.txt > /tm
p/SVEML_PALHC_MSRL3E144A_962203.txt.sedout')

Above sed command is to replace all the &1 text with
\\MCBELL4\BossTemp\NewAccount\LHCTEST2ERROR.csv. Unfortunately, the result
that I got is
<MCBELL4BossTempNewAccountLHCTEST2ERROR.csv>. All those \ character went
missing. I assuming this is because \ is a special escape character. Is
there a way to tell sed to ignore applying of escape character?

thanks