Changing regexp to single \ for message printing

[Heime]

I would like to have a function that takes a regexp such as

"\\(\\s-*\\[\\-\\] \\)\\(.*\\)"

that removes the extra \ in \\ but also add the necessary \ characters
to get another string that when used in message will print the regexp 
string with the single \.

I have tried to do the conversion myself but cannot get things quite right
with "\\(\\s-*\\\[\\\-\\\] \\\)\\\(.*\\\)\" because it is giving me

"\(\s-*M-x \-\ \)\(.*\)"

Whereas I need to get

(message regexp-display-string)

\(\s-*\[\-\] \)\(.*\)