diff --git a/dev/index.js b/dev/index.js
index 8d41fb2..d74e04d 100644
--- a/dev/index.js
+++ b/dev/index.js
@@ -9,4 +9,4 @@
  * @typedef {import('./lib/index.js').CompileContext} CompileContext
  */
 
-export {fromMarkdown} from './lib/index.js'
+export {fromMarkdown, md} from './lib/index.js'
diff --git a/dev/lib/index.js b/dev/lib/index.js
index 13a2395..c7c0a98 100644
--- a/dev/lib/index.js
+++ b/dev/lib/index.js
@@ -2,8 +2,10 @@
  * @typedef {import('micromark-util-types').Encoding} Encoding
  * @typedef {import('micromark-util-types').Event} Event
  * @typedef {import('micromark-util-types').ParseOptions} ParseOptions
+ * @typedef {import('micromark-util-types').State} State
  * @typedef {import('micromark-util-types').Token} Token
  * @typedef {import('micromark-util-types').TokenizeContext} TokenizeContext
+ * @typedef {import('micromark-util-types').Tokenizer} Tokenizer
  * @typedef {import('micromark-util-types').Value} Value
  * @typedef {import('unist').Parent} UnistParent
  * @typedef {import('unist').Point} Point
@@ -1142,3 +1144,41 @@ function extension(combined, extension) {
     }
   }
 }
+
+/**
+ * @param {TemplateStringsArray} strings
+ * @param {...Node} values
+ * @returns {Root}
+ */
+export function md(strings, ...values) {
+  // Interleave strings with U+FFFC OBJECT REPLACEMENT CHARACTER.
+  return fromMarkdown(strings.join('\uFFFC'), {
+    extensions: [{text: {0xff_fc: {tokenize}}}],
+    mdastExtensions: [{enter: {expression}}]
+  })
+
+  /** @type {Tokenizer} */
+  function tokenize(effects, ok) {
+    return start
+
+    /** @type {State} */
+    function start(code) {
+      effects.enter('expression')
+      effects.consume(code)
+      effects.exit('expression')
+      return ok
+    }
+  }
+
+  /**
+   * @this {CompileContext}
+   * @returns {void}
+   */
+  function expression() {
+    const parent = this.stack[this.stack.length - 1]
+    assert(parent, 'expected `parent`')
+    assert('children' in parent, 'expected `parent`')
+    // @ts-expect-error: Assume `Node` can exist as a child of `parent`.
+    parent.children.push(values.shift())
+  }
+}
diff --git a/test/index.js b/test/index.js
index fdf1a9a..97c3ed4 100644
--- a/test/index.js
+++ b/test/index.js
@@ -3,9 +3,9 @@
  */
 
 import assert from 'assert'
-import {Buffer} from 'node:buffer'
 import fs from 'fs'
 import path from 'path'
+import {Buffer} from 'node:buffer'
 import test from 'tape'
 import {unified} from 'unified'
 import rehypeParse from 'rehype-parse'
@@ -14,7 +14,7 @@ import {toHast} from 'mdast-util-to-hast'
 import {toString} from 'mdast-util-to-string'
 import {toHtml} from 'hast-util-to-html'
 import {commonmark} from 'commonmark.json'
-import {fromMarkdown} from '../dev/index.js'
+import {fromMarkdown, md} from '../dev/index.js'
 
 const join = path.join
 
@@ -1012,6 +1012,55 @@ test('mdast-util-from-markdown', (t) => {
     'should parse a thematic break'
   )
 
+  t.deepEqual(
+    md`*${fromMarkdown('a*b')}*`.children[0],
+    {
+      type: 'paragraph',
+      children: [
+        {
+          type: 'emphasis',
+          children: [
+            {
+              type: 'root',
+              children: [
+                {
+                  type: 'paragraph',
+                  children: [
+                    {
+                      type: 'text',
+                      value: 'a*b',
+                      position: {
+                        start: {line: 1, column: 1, offset: 0},
+                        end: {line: 1, column: 4, offset: 3}
+                      }
+                    }
+                  ],
+                  position: {
+                    start: {line: 1, column: 1, offset: 0},
+                    end: {line: 1, column: 4, offset: 3}
+                  }
+                }
+              ],
+              position: {
+                start: {line: 1, column: 1, offset: 0},
+                end: {line: 1, column: 4, offset: 3}
+              }
+            }
+          ],
+          position: {
+            start: {line: 1, column: 1, offset: 0},
+            end: {line: 1, column: 4, offset: 3}
+          }
+        }
+      ],
+      position: {
+        start: {line: 1, column: 1, offset: 0},
+        end: {line: 1, column: 4, offset: 3}
+      }
+    },
+    'should substitute an expression'
+  )
+
   t.end()
 })