Formatting a field by combining 2 fields and formatting the outcome

I want to combine the two fields [PARA] and [LN] and then add "CIV" to the end in the results, but I need the results to be 10 places. The fields are positions and line numbers from the manning document and I an creating a uniform ID based on the PARA and LN to have a a 10 digit alpha numeric ID being the result. Some PARAs are 3 digits or 4 and the result can only begin with a "0".

I am using MS 365 Excel the first line of data Column and rows are: PARA is (C4), LN is (D4) and result is (E4)