Blocking IPs with subnet mask

in .htaccess

[bobriggs]

Suppose the IP range is aa.bb.cc.224 - 255

In .htaccess, I want to deny this range. What is the subnet mask?

Deny from aa.bb.cc.224/255.255.255.31 ?
Deny from aa.bb.cc.31/255.255.255.224 ?

or something else? It's hard to test it. Right now I'm using
Deny from aa.bb.cc
but I don't want to deny from 0-223

[Brett_Tabke]

I don't believe there is a "range" operator other than the entire 256 ips in a c block.

[Key_Master]

SetEnvIf Remote_Addr "^aa.bb.cc.22[4-9]$" ban
SetEnvIf Remote_Addr "^aa.bb.cc.2[3-9][0¦4-9]$" ban

Place deny from env=ban within <limit></limit> tags.

This should ban every IP between aa.bb.cc.224 and aa.bb.cc.256