There is no option for doing that. Those scripts check "canadminusers", so you probably can't give an admin access to the user sections without also giving them access to subscriptions. But what you could do is edit admincp/subscriptions.php and change what it checks. The default looks like this:
Code:
if (!can_administer('canadminusers'))
{
print_cp_no_permission();
}
but you could add a different check, like for specific userids. Edit: Also, you'd need to make the same change in subscriptionpermissions.php.
If you wanted to get fancy you could probably add an admin permission for subscriptions. I think you'd start by adding a bit for that in includes/xml/bitfield_vbulletin.xml, and you'd probably need a phrase for the description of it, but I'm not sure offhand what else you'd have to do.