I have tried to deny international sites using the sample
<LIMIT>
deny from .de
deny from .it
deny from .ca
deny from .cn
deny from .au
deny from .br
deny from .ar
deny from .sw
deny from .uk
deny form .ru
allow from all
</LIMIT>
followed by the denied IP addresses. The actual IP addresses are not given for confidentiality purposes. The limit format will be accepted by my hosting company.

If I inputted *.de and a removal of the LIMIT tag will it work?
RewriteCond %{HTTP_REFERER} *\.de
RewriteCond %{HTTP_REFERER} *\.ru
RewriteCond %{HTTP_REFERER} *\.uk
RewriteCond %{HTTP_REFERER} *\.it
RewriteCond %{HTTP_REFERER} *\.ar
RewriteCond %{HTTP_REFERER} *\.br

How will this impact international visitors from seeing my site?

If RewriteCond will not work, can you suggest what will work if limit was removed?

Is there any altenative to inputting numerical IP addresses. My hosting company cannot accept CIDR format either. Both format will cause an Internal Server Error 500.