How do you create macro to move multiple numeric data from a vertical format to horizontal format using the plus (+) sign to separate each numeric data that does not have minus (-) sign.

Problem is:
-1
-2
-3
0
2
-1

Results required will be: (Note: resultes should be in one cell)
-1-2-3+0+2-1

Any advice or help will be greatly appreciated...Thank you