Rewrite to forward a URL with a space

Way back in the day, before I learned about Seo URLs, I was foolish enough to create a page with two words and no hyphen. The page has been redesigned, but the mod_rewrite rules I have been using to redirect pages are not working. I get the dreaded 500 when I use:

RewriteEngine On
RewriteBase /
RewriteRule ^Firstword Secondword\.htm$ http://www.site.com/firstword-secondword/ [R=301,NC,L]

Which is based on code I've used to forward other pages on my domain.

Naturally, the URL shows in the browser bar as site.com/Firstword%20Secondword
but when I try that in the mod_rewrite, there is no effect.

What am I doing wrong?

 

I have a feeling that percent signs may need to be escaped but I would need to check the documentation to be sure.

You may also get somewhere by escaping the space...

 

Pardon my ignorance, but what do you mean by "escape the percent" or "space"?

how would I do that?

 

Put a backslash before the space between firstword and secondword.

firstword\ secondword

Code (markup):

 

That did the trick! Thanks and rep to the two of you!