If you need to concatenate serious amounts of text (i.e >100000 bytes) together and you're using the regular & or + VBA concatenation operator you'll find that performance can be increased dramatically by using the little known mid$ statement. Here's what the HELP on mid says:
Replaces a specified number of characters in a Variant (String) variable with characters from another string.
Mid(stringvar, start[, length]) = string
The Mid statement syntax has these parts:
Part Description stringvar Required. Name of string variable to modify. start Required; Variant (Long). Character position in stringvar where the replacement of text begins. length Optional; Variant (Long). Number of characters to replace. If omitted, all of string is used. string Required. String expression that replaces part of stringvar.
The number of characters replaced is always less than or equal to the number of characters in stringvar.
So say I have a string variable 'data_block' with 900000 characters in it and I want to concatenate another string with 100000 characters onto it - say 'data_line'. Here's how you do it with mid
' make sure our data_block variable can accommodate 1000000 characters ' and our data_line can take 100000