Index: typo3/sysext/lowlevel/config/index.php
===================================================================
--- typo3/sysext/lowlevel/config/index.php	(revision 4425)
+++ typo3/sysext/lowlevel/config/index.php	(working copy)
@@ -234,12 +234,26 @@
 
 			// Variable name:
 		if (t3lib_div::_GP('varname'))	{
-			$this->content .= '<div id="lowlevel-config-var">
-			<strong>' . $GLOBALS['LANG']->getLL('variable', true) . '</strong><br />
-				<input type="text" name="_" value="'.trim(htmlspecialchars(t3lib_div::_GP('varname'))).'" size="120" /><br/>
-				' . $GLOBALS['LANG']->getLL('copyPaste', true) . '
-			</div>
-			';
+			$line = t3lib_div::_GP('_') ? t3lib_div::_GP('_') : t3lib_div::_GP('varname');
+			if (t3lib_div::_GP('writetoexttables')) {
+				// insert line  in extTables.php
+				$extTables = file_get_contents(PATH_typo3conf . 'extTables.php');
+				$extTables = '<?php' . chr(10) . preg_replace('/<\?php|\?>/is', '', $extTables) . chr(10) . $line . chr(10) . '?>';
+				file_put_contents(PATH_typo3conf . 'extTables.php', $extTables);
+				$this->content .= '<div id="lowlevel-config-var">' . sprintf($GLOBALS['LANG']->getLL('writeMessage', true), PATH_typo3conf . 'extTables.php', '<br />', '<strong>' . $line . '</strong>') . '
+				<br /><input type="submit" name="goback" value="' . $GLOBALS['LANG']->getLL('goBack', true) . '" /></div>';
+			} else {
+				$this->content .= '<div id="lowlevel-config-var">
+				<strong>' . $GLOBALS['LANG']->getLL('variable', true) . '</strong><br />
+					<input type="text" name="_" value="'.trim(htmlspecialchars($line)).'" size="120" /><br/>';
+				if ($this->MOD_SETTINGS['function'] != 3 and $this->MOD_SETTINGS['function'] != 5) {
+					// no write for $TYPO3_LOADED_EXT and $BE_USER->uc
+					$this->content .= '<br /><input type="submit" name="writetoexttables" value="' . $GLOBALS['LANG']->getLL('writeValue', true) . '" /></div>';
+				} else {
+					$this->content .= $GLOBALS['LANG']->getLL('copyPaste', true) . chr(10) . '</div>';
+				}
+				
+			}
 		}
 
 		$this->content.= '<br/><table border="0" cellpadding="1" cellspacing="0">';
Index: typo3/sysext/lowlevel/config/locallang.xml
===================================================================
--- typo3/sysext/lowlevel/config/locallang.xml	(revision 4425)
+++ typo3/sysext/lowlevel/config/locallang.xml	(working copy)
@@ -19,6 +19,9 @@
 			<label index="enterSearchPhrase">Enter search phrase:</label>
 			<label index="search">Search</label>
 			<label index="useRegExp">Use regular expression</label>
+			<label index="writeValue">write value to extTables.php</label>
+			<label index="writeMessage">Following line was added to "%s": %s%s</label>
+			<label index="goBack">&lt;&lt; back</label>
 		</languageKey>
 	</data>
 </T3locallang>
\ No newline at end of file