Merge values in a single cell based on condition

Hi All,

I am new to this forum as well as VBA. Kindly help me out with the following query:

I have a data set that looks like:
Script 1 Step 1 Comm
Step 2 Comm
Step 3 PD
Step 4 Comm
Script 2 Step 1 Finance
Step 2 Broner
Step 3 Broner

After I run the macro, it should give me the following result:

Script 1 Step 1 - Step 2 Comm
Step 3 PD
Step 4 Comm
Script 2 Step 1 Finance
Step 2 - Step 3 Broner

I have a sheet having 1100 such scripts spreading across 30000 rows. Any help in this regard would be highly appreciated.

Thanks in Advance..!