URLConnection/CURL assistance

I fail in translating a CURL command I found in web code.
Can someone assist me in translating this piece please?

	<form class="mod mod-LoadMore" id="mod-LoadMore" action="/ajaxsuche"
		  method="POST">

		
			<input type="hidden" id="loadMore_umkreis" name="umkreis" value="-1"/>
		
			<input type="hidden" id="loadMore_verwandt" name="verwandt" value="false"/>
		
			<input type="hidden" id="loadMore_WAS" name="WAS" value="baecker"/>
		
			<input type="hidden" id="loadMore_WO" name="WO" value="berlin"/>
		
		<input type="hidden" id="loadMore_startIndex" value="51"/>
		<input type="hidden" id="loadMore_position" name="position" value="51"/>
		<input type="hidden" id="loadMore_anzahl" name="anzahl" value="10"/>
		<div id="mod-LoadMore--block">
			<p class="mod-LoadMore--text">
				<span id="loadMoreStartIndex">1</span>
				-
				<span id="loadMoreGezeigteAnzahl">50</span>
				von
				<span id="loadMoreGesamtzahl">337</span>
				Einträgen
			</p>
			<a
					id="mod-LoadMore--button"
					class="mod-LoadMore--button"
					title="Mehr Anzeigen"
					href="https://www.mysite.de/suche/baecker/berlin"
					data-wipe='{"listener": "click",
							"name": "Trefferliste Treffer Mehr Anzeigen ",
							"synchron":false}'
			>
				Mehr Anzeigen (+<span id="loadMoreAnzahl">10</span>)
			</a>
		</div>


	</form>

What I tried is this, which basically returns a lot but not what I expected (Error code 404):

URLConnection1.RequestHeader("WAS") = "baecker"
URLConnection1.RequestHeader("WO") = "berlin"
URLConnection1.RequestHeader("position") = "51"
URLConnection1.RequestHeader("anzahl") = "20"

var s As String = URLConnection1.SendSync("POST", "https://www.mysite.de/suche/baecker/berlin")

Those are not headers, they’re form fields. They need to be sent in a POST with the content being something like

WAS=baecker&EO=berlin&position=51&anzahl=20

The values should be url encoded