I came 7 years later, I guess you don't need my answer anymore; However I struggled with sh lack of arrays too. so I came up with some weird idea, Why won't I make a functions that will replace the arrays? I mean... I'm bad at describing in words, so let me show you, and tell me what you think.

Even if it won't be useful for you, I want to believe that someone will find it useful. After all, sh is a bit tough...

Before we start,

#! /bin/sh

All the code will run on dash (/ash/sh).

array_length () {

    # The first argument of this function
    # is the array itself, which is actually a string
    # separated by a delimiter that we define in the
    # second argument
    array="${1}"

    # The second field should be the separator.
    # If it's not empty, set it as the local IFS.
    if ! [ "${2}" = "" ]
    then

        local IFS=${2}

    fi

    # So far not bad, 
    # Let's count the elements in this array.
    # We'll define the counter:
    counter=0

    # And now let's loop.
    # Pay attention, do not quote the string,
    # as it won't have the "array effect"
    for element in ${array}
    do

        counter=$(( ${counter}+1 ))

    done

    # At the end of the function,
    # Let's echo the amount.
    echo "${counter}"

    # Unset the variables (that's what I prefer,
    # you, of course, don't have to)
    unset array element counter

    # And I guess we can exit normally
    # unless you want to add a specific condition
    # (for example, if the length is zero,
    # the exit code will be bigger than 0).
    # I prefer that it will be 'true' in all cases...
    return 0

}

# Try it!
array_length 'Hello World!'

Now, You could use this idea for other ideas. For example, You want to find a value at a specific index:

array_value () {

    # Just like before, only few things are different...
    array="${1}"
    
    # Now the second argument is the index
    # to extract the value from
    # (think of it as ${array[index]}
    index="${2}"

    # Now we loop through the array
    # (I skipped the IFS thing on purpose,
    # you can copy and include it if you desire)
    # and once we match the index,
    # we return the value

    # Define a counter for each iteration
    count=0

    # Define the return status
    status=1

    for value in ${array}
    do

        if [ "${index}" -eq "${count}" ]
        then

            # It's a match
            echo "#${index}: '${value}'"
            
            # Set the return status to zero
            status=0

            # And stop the loop
            break

        fi

        # Increase the counter
        count=$(( ${count}+1 ))

    done

    # Of course you can add an return status
    # I'll set it to a variable
    return ${status}

}

# Try it!
world=$(array_value "Hello World!" 1)
echo ${world}

My code examples are released under GNU GPLv3 or later.

Tell me what you think about it, and if you like my ideas, feel free to use them!

If there's a better way to achieve these things with sh, Feel free to correct me! I'd love to get a feedback.