Changing URL in the searchform

Greeting,

Was wondering if anyone could help me adjust the searchform.php file:

Currently it is set-up to produce this kind of URL for search:
https://mysite.com/?s=foo&submit=Search

But I need it to produce:
https://search.mysite/main?searchtext=foo

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I am using the twentyelven searchform.php file:


<form method="get" id="searchform" action="<?php echo esc_url( home_url( '/' ) ); ?>">
<label for="s" class="assistive-text"><?php _e( 'Search', 'hypeMusic' ); ?></label>
<input type="text" class="field" name="s" id="s" placeholder="<?php esc_attr_e( 'Search', 'hypeMusic' ); ?>" />
<input type="submit" class="submit" name="submit" id="searchsubmit" value="<?php esc_attr_e( 'Search', 'hypeMusic' ); ?>" />
</form>