Sorry, I originally posted this in wrong discussion group (programming). I
would like to do this using existing Excel functions (non UDF).

Can anybody tell me how to do a conditional concatenate. I have to columns
of data. Column A has numbers: 1-5 (A2:A6). Column B has booleans:
TRUE/FALSE (B2:B6)

A B
1 TRUE
2 FALSE
3 TRUE
4 FALSE
5 TRUE

in B7 I want to do an conditional concatenate using "&" character on column
A using the booleans in column B. The result would like like this: &1&3&5.
Note there is a "&" before the first number as well.

Thanks