print ExpandRange$( "-6,-3--1,3-5,7-11,14,15,17-20")
end

function ExpandRange$( compressed$)
    for i = 1 to ItemCount( compressed$, ",")
        item$ = word$( compressed$, i, ",")
        dash  = instr( item$, "-", 2) 'dash that is not the first character, is a separator
        if dash then
            for k = val( left$( item$, dash - 1)) to val( mid$( item$, dash + 1))
                ExpandRange$ = ExpandRange$ + str$( k) + ","
            next k
        else
            ExpandRange$ = ExpandRange$ + item$ + ","
        end if
    next i
    ExpandRange$ = left$( ExpandRange$, len( ExpandRange$) - 1)
end function

function ItemCount( list$, separator$)
    while word$(list$, ItemCount + 1, separator$) <> ""
        ItemCount = ItemCount + 1
    wend
end function