Access SQL with variables

I have an INSERT SQL statement that I am using to append some data to a table. One of the values I would like to append to the table is a variable that VBA is using. How do I make this work? Below is m existing SQL statement...

strSQL = "INSERT INTO NGS_CAM_EXCEEDANCES ( DATE_TIME, OPACITY, [LOAD(MW)], " & _
"SLD_FUEL, GAS_FUEL, UNIT ) " & _
"SELECT Import_CAM" & piUnit & ".DATE_TIME, Import_CAM" & piUnit & ".OPACITY, " & _
"Import_CAM" & piUnit & ".[LOAD(MW)], Import_CAM" & piUnit & ".SLD_FUEL, " & _
"Import_CAM" & piUnit & ".GAS_FUEL, " & _
"VALUES ( NS" & piUnit & ") " & _
"FROM Import_CAM" & piUnit & " " & _
"WHERE (((Import_CAM" & piUnit & ".DATE_TIME) Between #" & pdDateAppend & "# " & _
"And #" & dDateEnd & "#));