Switch Command using variable for regexp

I am trying to use the switch command with the regexp switches.  It works when I explicitly use the pattern for the case.  I would like to make each pattern a variable.  This is where I run into trouble.  It doesn’t work.  I read somewhere that the curly braces surrounding the body of the switch statement needs to be removed.  Not successful there either.  

If the variable should match with style_1 it drops to default.  Any suggestions?

Here is a sample:

set style_1 {^[0-9]$}

foreach phone $List {

switch -regexp — $phone {

$style_1 {

echo “Style 1 found”

}

^[0-9][0-9]$ {

echo “Style 2 found”

}

^[0-9][0-9][0-9]$ {

echo “Style 3 found”

}

^[0-9][0-9][0-9][0-9]$ {

echo “Style 4 found”

}

^[0-9][0-9][0-9][0-9][0-9]$ {

echo “Style 5 found”

}

default               {

echo “Style default found”

}

}

}