Macro to concatenate cells in a range that skips empty columns

Hello,
I currently use
=CONCATENATE(A1," : ",B1," : ",C1) or
=ConcRange(A1:C1, " : ")
so that the contents of cells A1, B1 and C1 will display in D1 with a " : " between them.
Does anyone have or can anyone tell me of a macro that I can use that will take whatever I enter in various columns (let's say up to 10 columns) and combine the data to show only the final concatenation that includes the " :" between the content of each cell? It should skip empty columns and apply to all data filled rows in the spreadsheet.
Thanks.