Index: trunk/src/hid_cam.c
===================================================================
--- trunk/src/hid_cam.c	(revision 27427)
+++ trunk/src/hid_cam.c	(revision 27428)
@@ -476,24 +476,35 @@
 	return dst->exported_grps;
 }
 
+typedef struct  {
+	pcb_cam_t *cam;
+	const pcb_layergrp_t *grp;
+	const pcb_virt_layer_t *vl;
+	htsp_t *vars;
+} cam_name_ctx_t;
+static int cam_update_name_cb(void *ctx_, gds_t *s, const char **input);
+
 void pcb_cam_begin_nolayer(pcb_board_t *pcb, pcb_cam_t *dst, const char *src, const char **fn_out)
 {
+	cam_name_ctx_t ctx;
+
 	memset(dst, 0, sizeof(pcb_cam_t));
 	dst->pcb = pcb;
 	if (src != NULL) {
 		if (strchr(src, '=') != NULL)
 			pcb_message(PCB_MSG_ERROR, "global exporter --cam doesn't take '=' and layers, only a file name\n");
-		*fn_out = src;
+
+		dst->fn_template = pcb_strdup(src);
+
+		memset(&ctx, 0, sizeof(ctx));
+		ctx.cam = dst;
+		ctx.vars = pcb_cam_vars;
+		dst->fn = pcb_strdup_subst(dst->fn_template, cam_update_name_cb, &ctx, PCB_SUBST_HOME | PCB_SUBST_PERCENT | PCB_SUBST_CONF);
+		*fn_out = dst->fn;
 	}
 }
 
 
-typedef struct  {
-	pcb_cam_t *cam;
-	const pcb_layergrp_t *grp;
-	const pcb_virt_layer_t *vl;
-	htsp_t *vars;
-} cam_name_ctx_t;
 
 /* convert string to integer, step input beyond the terminating % */
 static int get_tune(const char **input)