@User It wasn't simple. 1. First, I did a awk '/^use.*¥//' on the ext file. 2. For each string, I did a manual search and replace /xxx -> _xxx In this case, we just had to worry about / in the instance name, but it's also conceivable that there could be slashes in the net name or both. CVC also uses / as a hierarchy separator, but it uses an adaptive hierarchy search. The instance path is first parsed on /, and the hierarchy is searched in order. If an instance is not found, the next instance is appended to the search string. At the last instance found, the remaining tokens are concatenated to form a net or device to search for. Spicevision, a spice -> schematic viewer, uses a hierarchy separator based on the input. For example, if an instance name or net name in the netlist has a /, spicevision may use a . as a hierachy separator. If the netlist has a / and a . , then spicevision might use : as a separator.