Shell Programming and Scripting

i have hundreds of directories that have to be renamed. the directory structure is fairly uniform which makes the scripting a little simpler.

suppose i have many directories like this */*/*/*abc* (in other words i have similar directory names 3 dirs deep that all contain the pattern abc in their dir name). i would like to rename any directory that contains the pattern *abc* to, say, xyz (or anything really, but not just change the abc part. i want to change the entire dir name with xyz).

there are several pattern variations that i would like to rename, so i'm trying to develop a script for which additions would be easy.

i'm using Unix (Solaris) with tcsh, and my work so far (i'm real green to scripting so there may be some mistakes) is:
.............................

foreach old ( abc )
set new=`echo $old | sed 's/abc/xyz'`
mv $old $new
end

.............................

this works for dirs with the exact name abc (and that's cool), but when i try:

.............................

foreach old ( *abc* )
set new=`echo $old | sed 's/*abc*/xyz'`
mv $old $new
end

.............................

it fails, saying mv: blahblah is a directory (or something to that effect)

i think that covers it all. if anyone wants to help but needs more info just ask.

thanks in advance for your help

quant