You can run something like this:
sqlcmd -S MyServer -d myDB -E -Q "select col1, col2, col3 from SomeTable"
-o "MyData.csv" -h-1 -s"," -w 700
-h-1
removes column name headers from the result-s","
sets the column seperator to ,-w 700
sets the row width to 700 chars (this will need to be as wide as the longest row or it will wrap to the next line)