I'm struggling with regular expressions

I have a sorcecode (Visual FoxPro & HTML) I want to change the case of.
All text, which comes after a < I want to change to lower case until
special characters >, ] or + occour.
For example:
send([<TABLE WIDTH="200" BORDER="] + xBorder + [" CELLPADDING="5">] + CR)
send([ <TR>]+CR)
send([ <TD COLSPAN="2"><B>HELLO</TD>]+CR)
I want to look like:
send([<table width="200" border="] + xBorder + [" cellpadding="5">] + CR)
send([ <tr>]+CR)
send([ <td colspan="2"><b>HELLO</td>]+CR)
which means, all text within HTML-Tags schould be convertet to lower case.
(Note the word 'cellpadding' also should be converted to lower case!)
Any idea, how I can achive this using TextPad 4 and reguar expressions?
Many thanks for any hint!
Best Regards
Juergen