diff --git a/embddr/common.scm b/embddr/common.scm
index 50859de..7efb175 100644
--- a/embddr/common.scm
+++ b/embddr/common.scm
@@ -19,6 +19,7 @@
           has-duplicates? find-duplicates
           insert-between
           string-replace-text
+          substitute
           read-template
 
           make-mux-selectors))
@@ -194,6 +195,15 @@
                       str))
                 str))))))
 
+;;; Substitute template
+(define (substitute text template-format subst-list)
+  (fold (lambda (s out)
+          (string-replace-text
+           out
+           (format template-format (first s))
+           (format "~a" (second s))))
+        text subst-list))
+
 ;;; Read template and substitute replacements
 ;;; Returns list of strings (lines)
 (define (read-template template-file template-format subst-list)
@@ -204,10 +214,6 @@
                     (if (eof-object? s)
                         (reverse l)
                         (loop (cons s l)))))))))
-    (map (lambda (str) (fold (lambda (s out)
-                          (string-replace-text
-                           out
-                           (format template-format (first s))
-                           (format "~a" (second s))))
-                        str subst-list))
+    (map (lambda (str)
+           (substitute str template-format subst-list))
          ls)))