The element variable {ce_first} is parsed inside every element and will be true (1) or false (empty) in a conditional to indicate if it is the first element for this entry.

Simplified case example:

{exp:channel:entries channel="your_channel" limit="10"}

	{custom_field}
	
		{heading}
			{value}
			<p>{if ce_first}This entry has <strong>{ce_count}</strong> elements.{/if}</p>
		{/heading}
		
	{/custom_field}	
	
{/exp:channel:entries}