I got your regular  expression to work but I had to make some minor modifications
myself. The program  I wrote is included below as well as my output. I just
output the whole match. I'm also assuming that you're using Apache's Regexp
package. The text  string might come out all garbled by posting it this way
(looks like a hyperlink in Yahoo's mail window) but you get the idea.

import org.apache.regexp.*;
public class TestRegexp {
public static void main(String[] args) {
RE re = new RE("insrsid\\d*([^\\{\\}]*)\\\\cell \\}");
String text = "{\\b\\f2\\fs20\\insrsid4223016 TEXT 1\\cell }\\pard \\ql
\\li0\\ri0" +
"\\widctlpar\\intbl\\aspalpha\\aspnum\\faauto\\adjustright\\rin0\\lin0
{\\f2" +
"\\fs20\\insrsid4223016 \\trowd
\\irow0\\irowband0\\ts11\\trleft0\\trftsWidth1 " +
"\\clvertalt\\clbrdrt\\brdrnone \\clbrdrl\\brdrnone
\\clbrdrb\\brdrs\\brdrw15 " +
"\\clbrdrr\\brdrnone \\cltxlrtb\\clftsWidth3\\clwWidth18610\\clshdrawnil "
+
"\\cellx18610\\row }\\trowd \\irow1\\irowband1\\ts11\\trleft0\\trftsWidth1
" +
"\\clvertalt\\clbrdrt\\brdrs\\brdrw15 \\clbrdrl\\brdrnone
\\clbrdrb\\brdrnone " +
"\\clbrdrr\\brdrnone \\cltxlrtb\\clftsWidth3\\clwWidth9370\\clshdrawnil" +
"\\cellx9370\\clvertalt\\clbrdrt\\brdrs\\brdrw15 \\clbrdrl\\brdrnone " +
"\\clbrdrb\\brdrnone \\clbrdrr\\brdrnone
\\cltxlrtb\\clftsWidth3\\clwWidth9240" +
"\\clshdrawnil \\cellx18610\\pard \\ql \\li0\\ri0\\sb100" +
"\\widctlpar\\intbl\\faauto\\adjustright\\rin0\\lin0 {\\b\\f2\\fs20"+
"\\insrsid4223016 TEXT 2\\cell }";
boolean foundMatch = false;
int startPt = 0;
do {
foundMatch = re.match(text, startPt);
System.out.println(foundMatch);
if (foundMatch)
System.out.println(re.getParen(0));
startPt = re.getParenEnd(0);
}
while (foundMatch);
}
}


The output I get is:

true
insrsid4223016 TEXT 1\cell }
true
insrsid4223016 TEXT 2\cell }
false

Actually I am using java.util.regex.* But you did point out a couple
mistakes in my expression. Below is the function that I am using.

//*****************************************
void reduce_rtf(String rtf)
{
Pattern rtf_patter = Pattern.compile(RTF);
Matcher rtf_match = rtf_pattern.matcher(rtf);
if (rtf_match.matches())
{
System.out.println(rtf_match.group(1));
}
else
{
System.out.println("No Match");
}
}
private final String rtf  = "insrsid\\d*(.*?)\\\\cell \\}";
//*****************************************
and rtf is

----
{\\b\\f2\\fs20\\insrsid4223016 TEXT 1\\cell }\\pard \\ql \\li0\\ri0
\\widctlpar\\intbl\\aspalpha\\aspnum\\faauto\\adjustright\\rin0\\lin0
{\\f2 \\fs20\\insrsid4223016 \\trowd \\irow0\\irowband0\\ts11\\trleft0
\\trftsWidth1 \\clvertalt\\clbrdrt\\brdrnone \\clbrdrl\\brdrnone
\\clbrdrb\\brdrs\\brdrw15 \\clbrdrr\\brdrnone \\cltxlrtb\\clftsWidth3
\\clwWidth18610\\clshdrawnil \\cellx18610\\row }\\trowd \\irow1
\\irowband1\\ts11\\trleft0\\trftsWidth1
\\clvertalt\\clbrdrt\\brdrs\\brdrw15 \\clbrdrl\\brdrnone
\\clbrdrb\\brdrnone \\clbrdrr\\brdrnone \\cltxlrtb\\clftsWidth3
\\clwWidth9370\\clshdrawnil \\cellx9370
\\clvertalt\\clbrdrt\\brdrs\\brdrw15 \\clbrdrl\\brdrnone
\\clbrdrb\\brdrnone \\clbrdrr\\brdrnone \\cltxlrtb\\clftsWidth3
\\clwWidth9240 \\clshdrawnil \\cellx18610\\pard \\ql \\li0\\ri0
\\sb100 \\widctlpar\\intbl\\faauto\\adjustright\\rin0\\lin0 {\\b\\f2
\\fs20 \\insrsid4223016 TEXT 2\\cell }
----