Dendrogram in R - (Mar/20/2012 )

How can I draw a dendrogram using my 01 scoring (in Excel) in "R" ?

there are many packages and options...first you should specify your question (e.g. type of clustering, what distance do you need (or other measures)) and then better ask in the R forums, or look for already finished discussions or prepared examples. There is a lot of help available and experts you can ask if you cannot advance on your own finally.

There's a good UseR! series (by Springer) book by Paradis called "Analysis of Phylogenetics & Evolution with R", which deals with drawing trees from matrices and other data forms. But I can't be more specific than that. As hobglobin says you need to specify the way you want the tree to be drawn; distances, parsimony, clustering or ML etc. If it's a 01 scoring in a matrix then is it a clustering? R packages featured in the book will do a UPGMA.