Contact Form 7: How to make 4 checkboxes in 1 ques a required field?

I have Wordpress Contact Form 7 Plug-in on my site. Need 4 checkboxes in 1 question to be a required field. As long as user ticks at least 1 checkbox, then the message will be sent successfully. Below will be the questions:

Which brand appeals to you?
[checkbox] cho [checkbox] ogpo
[checkbox] lho [checkbox] aico

Btw I can't group the checkbox together: (e.g)[checkbox* your-fruit exclusive "Apple" "Banana" "Grape"] because I need them separately for messaging syntax and styling purposes.

Below are the code that does not work:

<div class="col-lg-10 col-lg-offset-1 footer_cheakbox required"
style="margin-left:55px"> 

<div class="form-group col-xs-6 col-md-6
 marg_b" id="CH"> [checkbox  cho   id:ch  exclusive "cho" ] </div>

<div class="form-group col-xs-6 col-md-6 marg_b" id="OGP"> [checkbox
ogpo id:ogp use_label_element exclusive "ogpo"] </div>

<div class="form-group col-xs-6 col-md-6 marg_b" id="LH"> [checkbox
lho   id:lho   use_label_element exclusive "lho"] </div>

<div class="form-group col-xs-6 col-md-6 marg_b" id="AIC"> [checkbox
aico id:aico use_label_element exclusive "aico"] </div> </div> <div
class="clr"></div>

</div></div><div class="clr"></div>

Any help will be greatly greatly appreciated! Thanks!