You'll probably want to stick with ITL, if you can. You shouldn't need Perl code for this.
I haven't messed with IC in a while, but something similar to this (within the [query]
tag, of course) might work...
[if-sql-param hits >= 100]
<input type="submit" name="cv" value="Vote" disabled="disabled"><br><br>
[/if-sql-param]
I'm not seeing the point of outputting either a disabled button or nothing, though. You might just want to output the "disabled" attribute if the condition's true.
<input type="submit" name="cv" value="Vote"
[if-sql-param hits >= 100] disabled="disabled"[/if-sql-param]>
<br>
<br>